Credit card mess up at Checkers

On 25 July 2019 my husband brought groceries from the Raslouw branch. The cashier pulled the credit card out while it was authorising, causing the transaction to go through the bank and off the credit balance . She tried again and got an insufficient funds message. My husband tried to draw the money from the atm and transfer the money over but fnb was down. He left without the goods. Except for the cashier’s actions my husband are now out of the R800 plus money deductied from his credit card and got no goods for it. The manager’s behaviour was also a bad example of customer service she refuse to give him contact details of who he can query this with, didn’t give him any slip or proof. She didn’t care about this issue and said the bank will reverse automatically now the money is taken from his credit limit and he is sitting without proof and the manager didn’t offer to reverse the transaction. My husband now doesn’t trust the branch of Checkers and don’t want to shop there. Checkers what are you going to do to return my husband’s funds, and to train your personell to assist better in these situations and to process a credit card payment properly. This doesn’t happen at other shops