I recently rented from Avis at Innsbruck Airport. On collecting the fairly scratched vehicle, they checked and listed the damage.

When I returned the car there was no-one available for checking, so I had to return the keys to reception.

A week later I receive a further charge of 200 Euros for damage, of which there was none.

I have complained and they say they will investigate. Is there anything further that I can do?