Holding Fee

On the 16th of March I rented a vehicle from King Shaka Airport. The lady who was assisting me said she has to 1st reserve the rental amount + deposit on my car, of which the deposit will be credited to my account after I return the car. She then said she has to do another transaction of R3500 for a holding fee and swiped my card again, got bothe notifications from my bank for the 2 amounts debuted from my account. I returned the vehicle on the 19th of March, a few days later I was credited R1050 into my account which was the deposit from the rental. A week later I called 1st car rental to ask them to release the holding fee of R3500 as I don’t see why they are still holding the amount if they released the deposit, meaning the car is perfectly fine. Till today I have not seen that R3500 reflecting back into my account, I have been told that 1st car rental have released it, but it is not reflecting on my bank account. Please may I get my money back.