Final Warning and Handover

I have written prior reviews with regards to my billing problems I have with Vodacom despite me not having a contract with them any longer since July 2017. They advised in the review I wrote in Jan that they will clear all amounts. I was then charged a different amount of R149 for subscriptions and now received a final warning and handover letter. If Hello Peter is unable to assist because they actually do not even contact me is there another route I could follow to get this sorted out. I am listed negatively at the credit bureau and is unable to get vehicle finance now due to this. I really need this sorted out as soon as possible. This is now beyond frustrating and is desperately seeking this issue to be resolved.