AVOID AVIS CAR RENTAL AT LINATE AND MALPENSA AIRPORTS ITALY

We recently enjoyed a family holiday in Italy which included a prepaid 6 day car hire through AVIS Car Rental.
Our credit card was hit with two insignificant amounts which the bank rejected, but the bank failed to stop a third large request for $2102.00. Knowing our rental had been prepaid we notified the bank of the suspicious transaction immediately but they did not stop it based on AVIS information. The AVIS staff did not correctly register the returned vehicle. The AVIS staff did not give a receipt and when asked gave a receipt in another person's name. The AVIS staff used our credit card details without authorisation for 22 days car hire after we had left the country. This episode has ruined our holiday. The customer service from the Australian AVIS has been unsupoortive and terrible too. The company has become disreputable and I believe is corrupt at the Malpensa and Linate Airports. I would not recommend AVIS in Italy to anyone. I would have liked to know before our holiday other people's experiences so that we did not suffer this stress. Hopefully my review will help another unsuspecting traveller avoid the pain of being treated in this way by AVIS.
Incompetent staff at Linate airport.
Poor customer service.
Insecure credit card details and unauthorised use.
Possible corruption at a local level in Italy. (This is the only explanation!!!)