HERTZ BILLING ERROR and lack of follow up

Have been charged for a car rental for 22 days when i actually only had it for 1 day. I understand that mistakes happen but the problem here is that i am getting ZERO help from Hertz. i have emailed about 8 times and called, thus far i have received one email to say they have closed the rental off which means i have paid for 22 days which comes off my deposit. Hertz your car was ok but your afterservice SHOCKING