Still waiting for funds to be released

On the 8th of May I took a rental vehicle rental agreement number *** n returned it on the 12 May 2015 at 6:00am to this day I am still waiting for my deposit to be transferred to my account.I queried this at Avis in port Elizabeth n I was told that it will be sorted. To this day I have not received any response.I have 3 deposits of 1500 still held by Avis, this is ridiculous service.I have returned the vehicles unharmed and yet I have to wait with no feedback what's so ever about my funds.