Refunds not processed

On the 9th of June 2015 my insurance company arranged a curtsey car to be delivered for me at Sandton Proline Panelbeaters. As part of their process they debited R1450.00 from my credit card because I received the car with full tank. On the 16th of June 2015 I called their call centre for an extension and immediately R1995.00 was debited from my account. I informed the call centre agent that my insurance is paying for my rental and I don't understand why I am paying for an extension on a car rental. He promised to reverse that transaction within two days. My car was repaired and I arranged for curtsey car to be picked at the Wynberg Panelbeaters and I left it with full tank on the 23rd of June 2015. On the 25th I followed up on all my refunds R3445.00 (R1450.00 + R1995) was told their turnaround time is five days. On the 29th I followed up and was told that my credit card is invalid, the Bank cannot refund me but ironically it is the same card they have been deducting from. I was promised a call by close of business on the 29th of June 2015 however that did not materialise. I am being moved from pillar to post and would appreciate it if Avis can pay back the money...