MTN UNAUTHORIZED DEBITS ON MY ACCOUNT

I had a router contract with MTN on cellphone no *** that ended in October and I cancelled it . It was because we have network problems in Kinross and MTN never bothered to solve them. I called them on the 8th of October I spoke to a colored lady, she cancelled the contract and assured me that it is cancelled and the September bill was the last one because data was only credited on the 12th of the Month. The very same end of October I was debited the amount of R296,69. I instructed my bank to reverse the transaction because I don’t owe MTN. The end of November I received the second debit of R604,88. I again requested my bank to reverse the transaction. On Sunday the 6th of November I received an email demanding the payment from me and threatening legal action, for what because I don’t owe them. Is this another way of forcing clients to stay with the pathetic service we have to keep up with. They threatened to turnish my credit record under false pretense why is MTN this cruel, this is not the first time. Maybe it’s time the world nows about this.