Unsatisfactory service

There has been unexplained data usage on my contract pushing up my bill. I have made numerous attempts at contacting MTN Customer Care Centre to have a credit limit set on my account. I was told on more than one occasion that they were unable to assist me. They fave me a self-help number and I still was unable to placed a limit on my bill which was spiraling all the while. I then proceeded to send at least 5 emails to the Customer Care email address. Two of which received a generic email stating that I should go on their website for assistance or dial the self-help number and that a customer care assistant would contact me. Nothing has happened yet. I have been without my mobile for the last three weeks and I've had to get another mobile with a different number and get as many contacts to communicate with me on this new pay as you go number. I am a pastor and this has caused tremendous inconvenience for me and my congregation. To date I still have had no contact and I'm ready to cancel my contracts with MTN and return their phones. I've had it. By the end of this week I will be with another service provider. This problem was first reported on the 2 November 2015.