Holding deposit not received from Dollar Thrifty South Africa

I hired a car with Thrifty OR Thambo which was returned on 22 October 2018, the company held a deposit of R4000 on my card and was advised i will get it within 72 hours on return of the car. It has been 3 weeks since the the car was returned and I still have not received the deposit back. I tried calling ********** 454 and ********** 000 and have been sent from post to pillar with no clear direction and assistance. I was also advised that the only person that can assist is the branch manager from OR Thambo, however their phones are down (I have been told this for two consecutive days now). Service received is appalling.