I reserved a car online via www.avis.com , and rented a car from Zurich Airport, Switzerland for a one way rental. After returning the car, almost a month after return i was charged a "one way fees" of ~$540 for a one day rental !
Nothing in my car rental agreement when i initially booked the car, or when i picked up the car, mentioned anything about these charges. Additionally, they charged me "pre-paid gas" for USD ~100, although i never purchased the pre-paid gas, and returned the car full. Now, Avis customer service is asking me to produce a gas bill for car fillup, almost one month after the car was returned at an Avis location, and inspected by an Avis manager on-site in Paris, France.
Total rip-off. These people are credit-card happy. As long as they have your credit card, they will charge any amount on it. No explanation, no credibility to rental agreements , anything !