Avis car rental

Picked up a rental car from AVIS in Cape Town international Airport on the 4th June 2023, it was heavily raining and was never given some one to escort me to the car so as we can do a pre inspection, since well it was raining I couldn't check the car, got inside and drove to langebaanweg, the car was hired from the 4 to 10 June 2023 and that whole week was raining. Upon returning the car was asked about the right fender that had a miscolour, told the gentleman that pre inspection was not done and I was not involved in any accident with the car, then was told to sign that I got it as is on the 4 June 2023. Later I received a text saying that the damage on the car was not previously recorded its under investigation and today got a message billing of R28804 excluding vat and labour.

I can not be billed for damage that was not caused by me, if the investigation was properly done including checking of the tracker and impact report they would have seen that It never happened on the week I hired the car on. Reference number E***