As Mary Portas shows in her hit television show 'Mary Queen of Shops', you often have to be tough to get the best service from stores. But you also need to mug up on the law if you want to avoid being ripped off in either the real or the virtual high street.
The rules protecting shoppers differ depending on how you shop, with online buyers offered additional safeguards, mainly because you can't inspect your purchases in advance.
And for consumers taking out a financial product such as a loan or pension, there are cooling-off periods to give them time to ponder the financial implications of their deals.
Espe Fuentes, lawyer for consumer rights organisation Which?, says: "When buying in person you have rights under the Sale of Goods Act to return, reject or have the item repaired if it's not of satisfactory quality. But you don't have a right to return them just because you don't like them.
"Many retailers such as Marks & Spencer or TK Maxx allow a change of mind, but these policies are not part of your statutory rights, they are extra."
This is why you see that curious phrase "this does not affect your statutory rights" at the bottom of a retailer's returns statement - because its policy does not replace the law.
Shops offer these additional benefits as a gesture of goodwill, to keep you coming back.
John Lewis, for example, recently upgraded its policy - previously a 28-day no-quibble return arrangement - to a never-ending refund policy on returned goods so long as they are unused, unworn and accompanied by receipts as proof of purchase.
Be aware, however, that even tolerant retailers may expect you to keep the original packaging, if relevant, and may charge you if they have to replace it.
Fuentes warns: "You need to check each retailer's policy. People come a cropper because they assume they are entitled to return goods with no questions asked.
"I had a recent case when someone bought a sofa but had failed to measure their sitting room correctly, so the sofa didn't fit. The store did not take the sofa back, and legally it doesn't have to, as it's your responsibility to get the measurements right."
According to a Which? survey carried out in late 2010, just 18% of shoppers check returns policies before making a purchase.
[See also: Statutory rights explained]
Faulty or wrongly described goods are covered by tighter rules, with retailers legally obliged to replace them even if you don't have a receipt - although you may have to produce some proof of purchase.
"In this situation you have a month to return them," says Fuentes. "This can cause problems, as often people buy presents well in advance of a birthday or Christmas so that period has expired by the time they discover the fault. Because of that, you won't necessarily get a refund but might have to make do with repair or replacement.
"Under contract law, consumers have up to six years after purchase to return a faulty product."
The Trading Standards Institute warns consumers against being fobbed off by retailers that direct you to the manufacturer if your product is faulty. It says if goods are not of satisfactory quality or are wrongly described it's the retailer's responsibility to sort out the problem.
Even if the goods come with a manufacturer's guarantee, this is in addition to your consumer rights.
Goods might be marked down in the sales but you still have the same rights if they prove to be faulty or unfit for purpose. Shops displaying signs saying "no refunds on sale goods" are breaking the law.
Fuentes says: "Often you see something reduced because it has a button missing, but if you get it home and find the seam is ripped you're entitled to take it back."
Watch out for any changes to a store's own returns policy during the sales period - Monsoon normally allows 28 days, for example, but that reduces to seven days for sale items.
Shoppers buying remotely get extra protection. "The law recognises that if you've bought an item through a catalogue or online you need to ascertain what it really looks like," says Fuentes.
If you buy online, by phone or post, the Distance Selling Regulations 2000 gives you up to seven working days to return them or inform the seller if you're not happy. Both the value of the goods and the postage should be refunded.
The drawback for serial returners, however, is that they have to pay the return postage and packing charges - unless the retailer offers it as part of its own returns policy. Be warned: refunds are not usually allowed on CDs, DVDs and computer games if they are no longer sealed, unless they are faulty.
[See also: Your online shopping rights]
If you have a change of heart and cancel a confirmed holiday booking you're likely to lose your deposit or face a cancellation charge because you're breaking a contract.
You'll only be able to cancel a package trip if the content has changed significantly after booking. Sometimes you can transfer a holiday in the event of a death in the family - but not just because you changed your mind.
To cover yourself against a tour operator going bust make sure it's signed up to either the Air Travel Organisers' Licensing (ATOL) or the Association of British Travel Agents (ABTA), or a similar scheme which protects you against financial loss or being stranded abroad.
Think about taking out holiday insurance too - but check the policy's small print on cancellation and curtailment.
If you pay for your holiday by credit card, and it costs between £100 and £30,000, you may be covered by Section 75 of the Consumer Credit Act and be entitled to a refund should something go wrong, even if you booked individual elements of your holiday yourself rather than a package.
You will need to contact your card issuer. If it rejects your claim, take it up with the Financial Ombudsman Service (FOS).
[Useful: Compare travel insurance offers]
Buying a motor
When you buy a car from a car dealer or an online trader it must be of 'satisfactory quality', 'fit for purpose' and 'as described'. Failure to comply with these rules means you're entitled to a repair, replacement or refund, as with any other product, according to government-funded advice service Consumer Direct.
If you buy over the phone or through the web, you also have a cooling-off period of seven working days in which to cancel and get your money back.
You have fewer rights if you buy privately, as the car simply has to match the seller's description and be legally theirs to sell.
Phones and broadband
Always scrutinise the terms and conditions before signing up with a home phone, mobile or broadband provider - some may give you a cooling-off period (they must give you seven days if you sign up online or by phone) but others don't, which could land you with a charge if you change your mind.
If you have a broadband service that doesn't work for four weeks continuously, you're entitled to cancel the contract without penalty. If your complaint is unresolved within eight weeks, you can then contact one of two resolution services, Otelo or Cisas, depending on which provider you use.
Many financial products allow you to change your mind about buying without penalty, so long as you cancel within a set period. For credit agreements, such as credit cards and personal loans, the cooling-off period is 14 days. For general insurance it's also 14 days, and for life insurance and pensions, 30 days.
If you feel you have been mis-sold a financial product, you need to complain to the company first, and if that fails, seek redress from the FOS.
Mortgage borrowers can get out of a deal any time before completion, but you risk losing money if you've paid a valuation and certain other fees that are not refundable.
Once you have completed, if you want out, you'll have to pay the loan off somehow, such as by switching to another lender, and there may be early redemption penalties and exit fees that would make that option expensive.