AVIS service has become really bad.

Recently rented a car from AVIS from there M range. This was the first opting for a bigger car due to needed to fit a pram in the boot as I was traveling with a 3 month old child. The Avis I used was from the King Shaka Aiport. The car I recieved was a Nissan Magnite. When I first got the car the car had crack on the bumbers and tons of scatches to which when pointed them out the reply was noted. When i took the car I noticed that when breaking it was making a screetching sound. I called the AVIS office was told to take the car to the Umghlanga office to swop for another vehicle. I was then given a vw tcross. that vehicle had a few scratches and a dent on the drivers side. I took a video of this. I also made sure to let the person know and there reply once more was noted. When driving out I noticed the service light was on as this car was over due for a service. When returning the vehicle, I returned it to the airport and the person seemed adament I made the dent on the vehicle even though I showed him the video of the dent when i picked it.