Double Deduction

Almost a month ago my boyfriend had a work get together at Hooters Ruimsig. The evening was great and when it was time to pay for his bill, he paid but the amount was "declined" as was told to him by the waitress. So he payed again and the amount duly went through. The following day, whilst checking his transactions for the evening, he noticed that he was in fact charged twice. He went to Hooters Ruimsig and showed them all necessary proof and they assured him that the amount would be noticed and paid into his bank within a few days...This never happened. He has been in contact with the manager there and all that he keeps getting told is that they have been told from their bank that it needs to be authorised. This was a month ago. They never get back to you, you always have to follow up with them. Now I know an amount of R400 is not a lot to an establishment such as Hooters but it is to the normal man on the street. He even told the manager there that he doesn't necessarily want the money back, he could be given a voucher, just so that he could be refunded in some way. But nothing seems to get done about it. We tried corresponding with them directly and all we get is stories the entire time. This leaves a rather bitter taste in your mouth as Hooters Ruimsig is always such a great establishment to meet at. Hopefully this has not happened to anyone else.