I've just dropped off a rental car today and slightly scratched the rear bumper on a pillar in the pitch black car park.

I was told initially that it'd cost 340euros. When I questioned this I was told I could get a full cost in 1 week but 'Scratches' are never normally less that 200euros. I find this incredible as it was nowhere near such level of damage.

Any information on contesting the charges, or how these excessive charges are created would be appreciated.

Due to booking through a third party and a very complicated booking error by the hire company I wasn't offered the damage waiver.