If its their fault, they should pay, and if they refuse, leave bad feedback. that will ensure they don't get 50% discount on any goods sold for at least a month. so anything they sell will cost them 10% of the final value. and any future buyers will be wary. If you ordered it incorrectly, then you still have the seven day mail order clause, by law, they must pay return postage, even if its your change of mind, just saying you don't like it. If you buy it from a shop and don't like it, tough, you have no right of return, but mail order, you have seven days and they must pay the return postage, no matter what the reason.thats the law.