Final Letter of Demand for Vodacom's mistake !!

I had a problem in May, 2018 where my contract was updated without my consent. This was kindly sorted out by Wardah previously. On the 8/10/18, I received a 'Final Letter of Demand' for R206.31 which I had never received an invoice for. When I queried it I was told it was the admin fee for the upgrade - which once again was done without my consent. Since then I have tried numerous telephone conversations where I get transferred to at least 4 departments without any success. On the 9/10/18 at16.41, I spoke to Masala in subscriber collections who logged a dispute. This I was told takes 7 to 14 working days and I would have an answer, guess what, today is the 4/11/18 and I am still trying in vain to sort this out. Meanwhile I have been a Vodacom client since the beginning of time, they kindly cancelled my email and the number relevant to this complaint because of the outstanding R206.31. This must take customer service to a new level. In the letter I was threatened of legal action if I did not pay the amount but I am at my wits end as to how to sort this out ………...