After swiping the card, it is necessary to cancel the transaction or return the goods if there is a problem: (1) Return the goods on the spot: take back the signed bill from the merchant (triplicate) and tear it up; (2) Return after the event: Please ask the clerk to re-brush a negative amount as a refund for the original transaction in Dan Chong, and please keep the receipt of this refund form, or please handle it according to the existing regulations of the merchant.