1. Although the issuing bank has deducted the account, the system will automatically correct the transaction and the money will be automatically returned to the customer account because the POS machine has not received the success message.

2. The issuer debits the account, but the POS machine does not issue a reversal instruction, so the money may continue to be liquidated, or it may be debited at the issuer and will not be liquidated.

in either case, since the merchant does not have the certificate signed by the customer, even if the funds will be cleared to the merchant's account, once the customer complains, the merchant will lose the money.