paddyann report the problem to Amazon if the seller won't play ball. I would check first though that there is nothing on the product page about it that you missed. Even if there is something, unless the product information states the buyer is responsible for the cost of returning the item, the seller must pay the return postage. And don't pay it upfront.
I too had a delivery from Amazon today mine was two door curtains ...strangely they were differnt colours of blue and when I e-mailed the seller I was told they couldn't gaurantee 2 of the same colour so back they went..BUT they want to charge me the postage of £13 !! For something thats obviously not right and cant be used .
You could check your orders on Amazon just to make sure you haven’t been charged. It sounds as if someone printed out the wrong label. If you haven’t paid for it I agree with OldMeg. Just stick it in a cupboard and forget about it.
Just come home after meeting ex colleagues for lunch and found an Amazon package on the floor addressed to me. Inside is a telephone cable. No paper work or address to return. Has anyone had anything like this? I only use Amazon for my Kindle and there is nothing charged to my bank account. Strange.