PAY BACK MY MONEY!!!

On the 17th of December i collected the vehicle at AVis Centurion, all transactions done including my deposit, i returned the vehicle on 21st December, all the checks were done and all clear, today it is the 14th of January 2016 i still havent received my money i have visited this branch a couple of times now in search for my refund, i have been told each time email was sent to the bank and the bank must release the money i have also visited my bank who informed Avis must do this from their side, i am really tired of this nonsense i want my money refunded asw quick as they debited all their money from their account, nxa what **** service is this?