Rude customers at Budget Rent a Car

I work for a car rental company. Friendly customer service is a 2 way street. I get yelled at by customers and im told I have poor customer service skills just over stuff that I'M TOLD TO DO by my boss and by situations that is decided by upper management NOT ME. I also get yelled at when I politely remind a customer of there terms and conditions on there contract if a problem occurs. Over all the attitude I get from customers is they want to rent a car for next to nothing with NO coverages on the car and yet still NOT be held responsible if they damage the car or forget to refuel. If you ask them about the damage if it occurs they play stupid and say they didnt do it and there not going to pay (anybody can say that). If you rent a car, sign a contract and decline coverages and damage it then please own up to your own stupidity and shut up and pay the bill. It might also help if you carefully READ the terms and conditions for that is why there posted.