Bad service. You're *****ing our money

On the 24th of May my insurance company send me to get the rental vehicle at Avis for thirty days(30 days) then I was Requested to pay an amount of R1500.00 for security purposes, I did pay it via credit card. June 24th I returned the vehicle, they told me I will get the money back into my acc after 30 working days even now I haven't received my money, when I call them they refer me to my bank starting to blame my bank. Also when I call them telling my name they dropped my calls. I'm so frustrated by their customer service. I want my deposit back. It's been more than 30 days now.