Do not use AVIS!!!!!!!

If I could rate it zero stars I would. My insurance company referred me to AVIS when my vehicle went in for minor repairs. Firstly I confirmed with AVIS to deliver the rental vehicle at the panel beaters, phoned them 3 times to confirm, even on the morning as well. Waited half hour before I contacted my husband to fetch me and take me to the branch rather. When I collected the car, I said the petrol gauge is not full. MK said it is a glitch with the car and assured me it was. Picked it up the Monday and was notified the Thursday afternoon that my car is finished. Before I took the car back, I refueled and made a recording of the full tank as well as the petrol gauge and KMs. The gauge still showed it was not full even thought the petrol attendant showed me it cannot be filled anymore. (as per my recording) I drove a total of 97 km and paid more than R220 rand to fill up the car. I phoned the branch, spoke to Leigh and told her I have the receipt, video of the full tank and can send it to her. She said it was not necessary. So to my surprise I receive an invoice from AVIS which shows that they charged me for refueling of the car??? I tried to phone the branch and am still waiting for Leigh to phone me back. Laid a complaint with customer services , was contacted by the Centurion Branch Manager who said she will provide feedback within 3 days, NOTHING!!!! Have sent numerous mails and have phoned the branch again. SO I guess they are ignoring me. What do I do? Do I lay a complaint for theft? I want a full refund and lift of the hold on my credit card. I don't even want an apology since it would not be sincere. Just pay back my money.