I got this when I did a google for: uk distance selling regulations returns can i open the package

"Packaging: Under a distance selling contract, a supplier cannot make refunds subject to the goods being returned unopened in their original packaging. One of the principles of the distance selling regulations is to give you a chance to examine the goods at home, not having had a chance to do so in the shop. It would be impossible for you to do this without opening the packaging and trying the product out. Having said this, you will still be under a duty to take reasonable care of the goods while in your possession, and may be subject to certain instructions such as not to wear shoes outdoors, or remove hygiene seals. But you can never be penalised simply because you did not return the goods in their original packaging." ClickHere

The goods you can't return ClickHere

There are some goods you can't return if you simply change your mind, including:

1. CDs, DVDs or software if you've broken the seal on the wrapping
2. perishable and other items that deteriorate rapidly such as food and flowers
3. tailor-made or personalised goods
4. underwear and earrings