Olivauto Rent a Car

We had a relatively good experience with this car rental company for a 5-day rental and received a VW Cross (bigger car than we had reserved for but it was okay). The car was clean but the service was incredibly slow, which was fine. We returned the car, the contract was already charged, the tolls (which we agreed to pay in the contract) were paid afterwards and the tank of gas was filled up to full (8/8 bars). The lady mentions that they need to take the car to clean and its not likely at FULL, if the full bar drops to 7/8, they will charge the amount to fill 1/8 of the tank (which makes no sense because I'm no longer using the car at this point and how do you know how full" the actual gas tank was when it showed "full" when I received it - absolute subjectivity). Fine