Double Billing, no refund

I visited the Wang Thai Restaurant at Lagoon Beach on Friday, 8th December for lunch. All was good until the billing. My debit card was swiped and the R1,150 was deducted from my account but the restaurant's card machine indicated that it had not gone through. I was then told that it would rectify later and was asked to re-swipe my card. A second R1,150 was deducted and this then "went through" the card machine. I am now on the 12th constantly trying to get my refund of the double billing. They are requesting proof, even though this was reflected on my sms messages that I showed to the manager, Chollette, at the time. I have been in communication via email to "head office" as there is no contact number and just receiving the run around. I fail to see why I, the customer, should remain out of pocket for R1,150 due to their machine/banking issues while they avoid the refunding me. I am extremely frustrated and annoyed that I need to chase up on trying to get my money back.