I've sold a free gift (Armani bag) on ebay which i received with a perfume, is it fake?

I've received a giorgio armani bag with a perfume which I bought at Debenhams at their Gala Night, Sold that item on ebay. I've checked that other sellers selling the same item. Now buyers says the item is a fake, he wants to retun it + he wants return postage cost , what shall I do?|||debenhams would NEVER sell you a fake item. nor will any other store. online you have to be very careul.. just explain to hin and take a picture of a receipt. if he is still stubborn give him a refund and try to sell it to someone else. :D x|||It depends how much it cost. Armani is pretty expensive, so if it was a REASONABLE price, it was fake.