Never again another MTN contract

After being a client of MTN for 23 years, I am now finally cancelling ALL my MTN contracts. I have never received such bad service from a company. Their supervisors promise to phone you back, but never return any calls. After another 30 minute call today, the supervisor again promised to phone me back as he was not at his desk, but never called. I am charged for subscriptions I have not approved. They are not crediting my account as requested and are now creating a bad credit rating for me due to their incompetence. MTN you should seriously be asking questions if your long-term clients are cancelling contracts! Pathetic!!