Failure to Refund

I hired a car on 30 May 2015 and as usual a holding deposit fee of R3000 was held in my credit card. i further made extensions but later cancelled the booking and was expecting a refund which i was advised i will get within 21 days. The R3000 holding deposit was also used and when quering it, no one knew what was happening and i could not get any straight answers. I had to go to their office and was told that the manager was off duty, she would call me when she was available or i must come the next day. I have been waiting for the manager's call since as well as my refund and until today i haven't gotten any of that. When i called this morning to enquire again about my refund, seeing that 21 days has passed, they told me they would call me back as they needed to check what the problem is and it's gonna take time. The service there is so disgusting, looks like no one has a clue what happened to my money