Still waiting for my deposit a week later!!!!

I rented a car at Cape Town International Airport on the 9-11 September. Car was returned on the 11th. Till now I haven't received my deposit back of R6000. After numerous calls and the agents tells me that the deposit will be refunded in 48-72 hours. It's now a week later and still nothing has happened!! I need the money and get no help what so ever!! Very bad service!