Poor customer sevice

Hi I have been a customer for about 2 years at MTN since I moved over from Auto Page. I was about to upgrade when customer service said there is an amount of about R140 outstanding on my account. I queried this because I have been paying a little more than my montly installment for the last 3 months. In 2016 I had a problem with my account that we did sort out and i had too make a payment off over a R1300 to get my account up to date. When i queried thr outstanding amount they said it was insurance that was loaded on my account by Pinnacle Marketing (some insurance 3000). I contacted Pinnacle Marketing and cancelled it because I never gave permission for it . So they did the cancellation and I but the amount still showed outstanding. I contacted MTN for the last month and a half now to try and sort it out but they blame the insurance department and the insurance department blames MTN . So what too do now? They now keep on disconnecting my phone and I cant upgrade and nothing gets done . I personally think this is *****. How can MTN add insurance on my phone without my consent. Can anyone from MTN help me with my account