Europcar not checking their cars properly before hiring out to next customer

We hired a car at the King Shaka airport on 29 June 2018 at around 21h00. The car was checked in the dark and the key handed over to us. We returned the car on the 1st July at around 16.00 only to find that there was a slight dent on the right hand side of the car. I filed an incident report that I did not cause this damage. It was investigated and found that the gentleman cannot confirm that there was a dent. So I am still waiting for my deposit 17 days later. This is totally unacceptable and I will definitely not make use of Europcar in the near future.