Dollar Rent A Car

My flight had changed to a later flight so I ask them at the counter what the charge would be to return the car 5 hours later then originally rented for and I was told 47 dollars which I assumed would be for a full day 24hrs/daily I was billed 105 dollars for 5 hours... These people are crooks they just bill you as they feel fit and don't care about ever making it right with you. Two weeks prior I rented a car from them and had a family emergency come up and returned the car a full 24 hours early and they never even refunded my money for the one day early that they re rented the car and made double on it, crooks crooks crooks... They should be dealt with severely this should be illegal if its not.