A Struggle to get Deposit releae

On 7 October I hired a vehicle at King Shaka Airport for 4 days and on hiring the vehicle they put a hold on my card for R11,980 in case of accidents or damage which is an industry norm. On the 10th I returned the vehicle with a full tank confirmed no scratches or dents on the vehicle all good. On 14 October they sent me the invoice and duly took the fee for the hire off my card and the transaction was concluded. Since then the hold of R11,980on my card has remained so I gave it a few days but nothing. I sent an email and got no response so I decided to call the Johannesburg office and I requested the hold be released on my funds. The person said I must contact the my bank. I rep**** that their company had put the hold on my card they must call the bank and release the hold. I find it strange that the system seems to have changed when the transaction is concluded the hold on the funds are released shortly after but on the last few occasions it has been a mission to get them to release the hold which is very frustrating. It makes you not want to hire a vehicle anymore and rather Uber around it is less hassle.