The most likely reason is that the payment credit card of the buyer's account is abnormal (black card, automatically generated), or the stolen gift certificate card is used to trigger security risk control and lock the account. Amazon will ask for credit card bills. In this case, the buyer's account must be unlocked to log in to the corresponding Amazon seller account. If the buyer's account is bound to a real credit card, just provide the corresponding bill. If you can't provide it, you are not optimistic.