Beware of Avis Sandton

I have hired cars from Europe Car, Budget and Thrifty, all without incident. On 5 October 2021 we took delivery of a Polo Vivo from Avis Sandton with all the usual paper work and checks. Avis is situated in a ba*****t so lighting is not so great. The gentleman who does the checks went round the car quite quickly noting any scratches or dings. He didn't check under the front bumper which you would never really see anyway because it's under the car. When we dropped off the car yesterday morning, he directed me to park in a much brighter spot and gentleman does a thorough check, looking under bumpers etc. He then says to me there's a scratch under the bumper. I personally took the utmost care driving this vehicle, never once striking the bumper on anything. I tried to disagree but was asked to sign the paper work for the scratch which I did sign for, as I needed to get to work. I enquired how much it would cost and quite conveniently he says R1500, which is the entire deposit amount. I was going to let it be but I noticed there was also another car that came in at the same time as me and he was told the exact same story (bumper scratches). Reading all the comments here it seems like many people have experienced the same issue with being told that the bumper under the car was scratched, which seems like an excuse to retain the deposit. Just a warning if you use Avis Sandton, insist they park the car in a brightly lit area to do the checks and make sure you check under the bumper, as this seems to be the prime spot where they search to claim you scratched the car or better still just use a different provider or Uber to avoid being ****med.