Dollar Thrifty pathetic service

I hired a car at Durban Airport and was told to pay R9000 as my card is a debit card. This was NOT on the Terms and Conditions! Anyway I paid this and 3 days later brought the car back in same condition. I am waiting for my Deposit till this day. The car was returned, so why should I wait. This is appalling service. I will Never use Dollar Thrifty ever again!