First Car Rental Dishonest

Pathetic service...rented a car when my vehicle went in for repairs... upon handing over the vehicle I specifically asked is everything okay do I owe them anything I was told No everything in order....I get a nasty SMS from credit control im in arrears with First Car Rental R538.00.... I called first car rental to enquire they said they will get an agent to call me...I mow get a call from Fusion says I'm owing money why haven't I paid...I'm still waiting for first car rental to get back to me....the last was honest in saying I'm owing toward E tolls..... why wasn't this communicated to me upon signing the rental agreement.... very frustrating!!! Will go back to First car Rental...my FIRST and LAST time!