If I don't open a product am I allowed to return it?

[Ricochet J]

Lets say I purchased item x from a shop via the net and it comes delivered tomarrow. If I don't open the package and return it back to the shop will I be able to have a full refund?

I've changed my mind about a product which will be arriving tomarrow and would rather buy a similar and better product from the same shop.

 

[Ricochet J]

reject it, tell em to return to sender

Already paid for it yesterday so it will come out of my card, which means i'll be left with no product!