Hard to get a refund after paying twice

Myself, my boyfriend and my brother are on holiday in Cape Town. It's our first time. We were happy to come a cross Quay 4 at the Waterfront and decided to have our Christmas lunch there. We had a good time and the food was amazing. When it came time to pay the bill they told us it had not gone through and asked us to pay again (this amount was R600). In total we paid R1200 and it showed on our bank that it had gone through twice. Instead of refunding us we had to wait up to 4 days just to get a response from them about the refund. They now want bank statements and for us to print and fill out a form. They then tell us after doing that they still need to investigate and it could take up to a week for the money to come in. This is what we have to do to get our money back. Not only are we staying 1 hour away from town but we actually live in PE and need our money for petrol to get back home. I'm really horrified as this has put a huge damper on our holiday. No one called us back, we had to run after them and call sometimes twice a day. We almost feel like it's an inconvenience for them and as if we are the ones who made the mistake. I really feel the restraunt is not concerned at all and couldn't care less if they never hear from us again.