1. Although the card issuing bank has debited the account, since the POS machine did not receive the success message, the system will automatically reverse the transaction and the money will be automatically returned to the customer's account;

2. The card-issuing bank deducts the amount, but the POS machine does not issue a reversal instruction. The amount may continue to be liquidated, or it may be debited by the card-issuing bank and will not be liquidated.

No matter the above situation, since the merchant does not have the customer's signature confirmation certificate on hand, even if the funds will be settled into the merchant's account, once the customer complains, the merchant will lose the money.