Avis Rent-A-Car Extra Charges after Daily Rental Queens New York

 My wife and I just rental a car through Avis Rent-a-Car located at JFK airport.  When we rented the car, we were told that the gas should be brought back in with the same amount as when we left the station.  The meter was on full when we left and the gas meter was brought back on full as well. 

We were later charged over $30.00 more than the estimate since we drove out of the lot and did not show proof that we put gas into the car even though we were not told to do this when we got the car or mentioned on any documentation we received.  They said that since we drove out of the lot, that obviously gas was used.  We came back with saying the gas meter was on full when we brought it back.  They said it needs to be "topped off" and show proof that it was topped off since the gas meter will stay on full the first 70 miles it is driven (none of this was said to us originally).

I only want to be charged what I feel is warranted and feel this is a crummy way to do business.  We brought the car back with the gas meter on "full" and because we did not show proof that gas was put in, we get charged over $30.00 in fees for driving a car only a few miles.