Pathetic service and **************** by AVIS!

OUTsurance supp**** me with a rental car as my car was in for repairs.I work at ORT Int and was advised to collect the car there.On phoning avis I was told that I have to collect before 7 in the morning or wait till 7 the night. I worket a 05h00 to 13h00 shift. I sneaked out from work to collect car.I signed and recieved the keys.I jumped in the car and rushed off to get back to work.On my way to work I noticed a small 3mm x 3mm chip in the corner of the window. I didn't think anything of it as I have rented many cars from avis before with minor damage on. On returning the car I was asked about the chip,I explained and the guy said its fine I must write it in my report.I also filled the cars tank before returning.6 days later AVIS takes R3900 off my acount(my waiver for writing the car off was only R3070)R3500 for a brand new window and R385 for fuel.(tank was full) After more than an hour on the phone I went to MR Muzi at ORT branch. He was in no way willing to assist.He kept me standing there for more than an hour then said he was going to escelate it to his boss Sandry and promised feedback within hours.4 days later and 10+ phone calls to the guy and still no reply???