Avis Overcharged My Account & Blacklisted My Name

I rented a car with Avis over a year and a half ago, they over charged me and refused to pay me for over a year period although I was pointing out that they had actually overcharged my credit card. I was talking to the branch manager at Rivonia Crossing & Petro Laurence but they refused to pay me while they had duplicated the invoice to charge me double the amount. Further to double charge they took me to their credit collectors and over a period of 12 months of trying to prove that Avis was infact in the wrong and I had been overcharged even after the fact that I had raised the duplication issue Petro L continued to bully me with rude emails and calls.<br> I was then introduced to Marcelle Forster who tried to resolve the issue and wrote an email confirming that there had been an double charge on my account and wrote to their credit controller that they Avis had made a mistake and that they are withdrawing the account from their service provider. Marcelle confirmed in writing that they would refund the money this after a year and a half and countless emails to and fro which they did. In December while trying to get a car my deal was rejected because of their listing at credit bureau.