Keeping security deposit beyond the stipulated time

I hired a car on the 19th of August and returned it on the 24th August at King Ushaka Airport. The problem now is the company has not released my deposit up to date. I called them Friday and I was answered by a lady that was full arrogance, she told me their merchandiser will make a call to the bank and I must give it 24 to 48 hours no apology nothing.