High-street shops don't have to accept returns unless an item is faulty, but online purchases are covered by the Consumer Contracts Regulations
The Consumer Contracts Regulations
When you buy goods online you have additional rights to return them.
This is because your decision may be based on a brief description or a photograph - so what you receive isn't always quite what you'd expected.
under the Consumer Contracts Regulations
you have the right to return your order up to 14 days from the day you receive your goods.
Many online retailers extend this even further so be sure to read the terms and conditions carefully as you may have longer to return unwanted items.