Deceiving and unprofessional

I hired a car from Port Elizabeth airport on the 24th of December. I was told only 1 car is available for hire and no other car, R2800 was held on my card. the problem was when I went to inspect the car, there was nobody from budget to inspect the car with me or make any record of any damages, my car pickup was 18:30. I noticed that the bumper was damaged on the side but there was nobody to report the damage to. I took the car as they had said it was the last one. When I returned the car on the 30th of December I was asked to fill in a form and explain that I received the car with damages. The R2800 was returned to my account but then R4752.18 was debited from my card. I received an sms sayin I have been billed because of damages to the car but I never damaged the car at all and I returned clean with a full tank. I called every number on the websites, I even called the number on the sms, and the airport manager Nadia Lawrence was told to get back to me after investigating, she never did. I even went to the airport to report the matter, i was told an email woukd be sent to the bank but still nothing happened resulting in my card being in arrears. I want my money back.