Avis skeem

Avis is the car hire linked with my discovery insurance, I hired a car due to a accident I had with my vehicle, but then I paid a R2000 deposit cash, the 1st car they gave me was faulty so when I complained the gave me another car but this was last minute so I didnt have time to clean or fill the tank, so the 2and car arrives and I drove it for a month, when they picked it up the lady said everything's fine from the full tank to the car being clean, then I waited 2 weeks for payment and still waiting so from R2000 they giving me back R800, the worst part is no1 contacted me to explain me the bill and also when I went to the offices the lady said my only charge is the etoll which is 450, but now after sending about 8 emails to the so called customer care they just rep**** that they fill 2 cars with full tank petrol, now also another concern is the lady that picked the car up came at 4:30pm and she had a passenger obviously taking the car home, so which is charging her for the petrol used to get to her place or wherever she goes and returning after using the petrol I filled..no explanations, no customer client relation, no sympathy basically they give 2 wits about..that deposit is a skeem they will do anything to keep most of that money, I will never hire a vehicle let again from avis