Held responsible for damage to a hubcap that I did not do.

I hired a car in CT recently. I was handed a form and told that I was to take pictures of any other issues that I noticed on the vehicle which I did. There was nobody to check the car out so I got into it and left. On returning the vehicle, I was told and shown that there was damage to the front left hubcap. I had not noticed or looked at the tyres when I had collected the car and stated that I did not do this damage. I have now been charged almost R2000 for the hubcap which is ludicrous. I called Suzuki and these items do not cost more than R700. How is this allowed or possible? I could still accept paying for the item but why should I pay R2000 with no email, invoice, letter or other communication advising this amount or how it is made up. Shocking service as they should have had a staff member go through the checklist as well as the car to verify that they had not missed the damage when it was last checked. My partner and I have used them frequently but this will definitely not be the case going forward. How can it be permitted that cars are not physically checked out by a staff member where all the checkboxes are covered and one can see if there is additional damage that was not picked up?