Mtn account problems -

I upgraded my mtn account via phone. I recieved numerous sms's from mtn about thos account. 2 problems 1. They keep on overcharging me. When I correct this I recieve an SMS confirming the correct amount and then mtn just overcharge me with the following accounts. I gave stated numerous times that I dont give permission for any extra services. 2. Mtn charged me for insurance on a phone that I dont have. I never asked for insurance or gave permission that any insurance may be debited against my account. Contacting them they told me I have to proof that I didnt ask for insurance on a phone that I dont have. How do proof that more than saying tbat you didnt asked for it. I was told that I must go to Bloemfontein to the shop where the insurance was registered. I live in Modimolle ****m away. How more ridiculous can Mtn be? Marius Bacon