Unpaid Refund/deposit

My insurance company rented a car from AVIS JHB for me as I submitted a claim. When the car was delivered to my place (04/01/2016) I paid an amount R1,200. The car was returned on the 27/01/2016. My deposit had to be paid in about 5 business days (03/02/2016) but noting was paid. I've continuously called AVIS requesting for my deposit to be paid back, and still nothing. Can someone from AVIS please assist as this has been the worst car rental experience I've ever had. I will definitely not use AVIS car rental in the future. My whole experience has been very poor. I still haven't been refunded and its the 03/03/2016.