or see if Amazon will track down the owner and notify them/return it..is there a name on it? if so you might be able to track the person down yourself..but if there are multiple people with that name might not be a good idea...
if it really is a credit card, it can and should just be cancelled--a thief could have had it before you, but if it is a gift card, the funds would be lost to the owner.
if it is a gift card, it could have been used up and then just turned into litter
Private message me with your name.