Failure to refund deposit

Rented a car for one day en returned same on 17 December 2015. A week later and the exhorbitant deposit of close to R10 000(yes for one day's rental) has not been returned to me. There is no basis in fact or law for the deposit to be retained for any period after the car was returned. What is Europcar doing with all the exhorbitant deposits it is not returning?investing for their own interest benefit? Phoned call centre twice only to be told it has been processed and there after another employee advised that the transaction is not yet invoiced.I want my deposit returned today Mr Calvin May,not a generic reply email advising that you are looking into the problem.<br> <br> Johan Nysschens