One problem that can happen with debit or credit cards is a double transaction. This happens when a merchant accidentally runs your card twice for the same transaction, which causes your account to be charged twice unnecessarily. This type of problem is usually resolved fairly easily, although you can expect the reversal of funds to take several business days. If your account balance is low, a double transaction can cause your account to suffer overdraft charges.
Locate your bank statement or print out your online banking transaction history. You'll use this to prove that your debit card was charged twice by the merchant. If you are dealing with an online or telephone transaction, you can omit this.
Visit the merchant in question. Ask to speak with a manager. Explain to the manager that you have been charged twice for the debit card transaction. Show the manager proof, if necessary. If you are dealing with an online or telephone transaction, call the customer service number and ask to speak to a supervisor.
Tell the merchant that you need one of the charges to be removed. Ask him how long the process will take. In general, you can expect a reversal to take three to five business days.
Check with your bank after the allotted time. Ensure the transaction has been reversed.
Contact your bank if the transaction has not been reversed. Explain to your banker that you were charged twice for the same transaction, and that you asked the merchant to reverse it, but had no luck. Your bank will be able to investigate the situation further and likely resolve it for you.
If your account has been charged overdraft fees, ask your bank to refund them due to the situation. If it will not, request that the merchant pay you for the fees because the overdraft is not your fault.