Avis did rthat to us in New Zealand
We had to rent two cars on the North and one on the South island as Avis does not let you take them on the ferry
The rental car on the North Island was new with no damage. The rental car on the South Island had a little damage that was noted on the slip of paper that I fortunately kept.
After returning to the US we had a charge of about $1,000 on the credit card which I disputed. They came down to around $400 because they could fix it in house. When I asked for all the documentation, they sent photos of scratches under the bumper you never would have seen. But the kicker was that that slip of paper I had documenting the damage on the car showed damage there when I received it. They sent the slip of paper for the car on the north island with the damage on the south island but the license plates did not match. They finally sent it back to New Zealand and the charges were removed but I would have been out of luck if I didn't save that paper showing the damage on the car.
It was a hassle with Avis who claimed they were the middle man because it was a franchise. But when I finally got someone to look at it which was difficult they sent it back and the charge was reversed I am sure it was a racket and that many people would pay the $400 as they would be grateful it wasn't the $1,000