Double Billed, Impossible to Cancel

I have been double billed since October 2018 and have tried everything in my power to cancel my contract, yet every month I get double billed again and again for a service that I have not been using in months. I want my services cancelled immediately and monthly bills since the previous dealings with Telkom s****ped. I was actually refunded for being double billed and then continued to be double billed again. I honestly have zero interest in dealing with anything Telkom anymore and will definitely not be paying this ridiculous R6650 outstanding double billed balance for services I no longer use. Account number ***