1. Dealing with faulty goods

Under the Consumer Rights Act, goods should be fit for purpose as described, and of satisfactory quality – which means if what you buy is faulty or doesn’t match what a salesmen promised, you could be in line for a refund. But you need to act quickly as you only have 30 days in which to reject something that's faulty and get your money back. Once this timeframe has run out, you can ask for a free repair or replacement. If that repair or replacement is unsuccessful, then you're entitled to a refund.

More here:
​http://www.which.co.uk/consumer-rights/problem/what-do-i-do-if-i-have-a-faulty-product​​

2. Returning unwanted gifts

Our research found that two in five people falsely believed that if you buy something from a shop on the high street, you have a legal right to a refund if you simply change your mind and wish to return it.

Legally speaking, shops only have to accept returns bought on the high street if they’re faulty - they don't legally have to accept something that you decide you don't want. The good news is that most retailers do have a returns policy offering an exchange, refund or store credit for most returns. And if they do have a returns policy, they have to stick to it.