Worst experience with car hire

Hired a car from Tempest car hire. It was full of scratches, and the brakes were s****ing terribly. Noted all the scratches when it was delivered. But when it went back, they have now billed me for a dent in the car that isn't even there. I've got pictures of where the dent is supposed to be, but you cant see anything. I was forced to sign that there was a dent, which I couldn't see unless the car was inspected at a certain angle with a light being shone on it. The person who collected the car was extremely intimidating and rude.

I am still getting threatening phone calls from them about the so-called dent.

Photographs of the car can be provided on request. I will never recommend them to anyone.