Deposit not refunded!!! Pay back the money!!!

I hired a car from Avis from EL Airport. They subsequently blocked R3500 from my account when I took the car on Friday, 28th June. A day or so later they provided me with the invoice with all the charges but its been five days or so and the money which was blocked wasn't returned to my credit card/account yet??? This utterly unacceptable as they take a spilt second too deduct the amount from you but you must wait weeks to get yours back??? I want my money asap!!! Pay back the money!!!