Bad service

I rented a car for a day at Avis Merlyn (R/A No. ********** 84) on the 13 May 2019. First they wouldn't allow me to leave my car in their premises and second when I brought the car, it had a small chip on the windscreen because a truck hit on the highway as I was driving behind it. I reported this to them and I had taken an insurance. The guy who assisted me, told me that due to the insurance, I will charged an admin fee of R90.00 which was on written in red the rental agreement. I never objected to this. On the 29 May, I enquired about my bill as I was getting anxious because they got back to me about my bill as promised. I was told I could have received an sms, and the statement which I never did informing me about the bill. The guy who was assisting immediately sent me the bill via e-mail and the there now a debit of R360.87 which I was told was an admin fee. I disputed this due to previous information. He then promised to escalate this and immediately after our discussion, an sms came indicating, the amount was for damages. How does Avis operate really. This is bad service for me. Still waiting for clarity as this contradicts previous provided information and my Credit Card is still not refunded as they took more than what I was billed.