Appalling service-the worst I have EVER experience

I took out a new contract in December 2014. A Blackberry internet service has been charged for ever since, despite the fact that I have never owned and never will own a Blackberry. When I complained to MTN, they said I had to send them a copy of the contract to prove to them that I never requested this. So guess what-I then requested MTN to send me a copy of the contract, which I then SENT BACK to MTN , which proved my point!!!! I was then told to give them, via non secure email , confidential details pertaining to my account,such as my pin, FOR SECURITY REASONS. I refused and said they could call me for these details, which they refused to do( we dont call customers) I tried to call the 808 number-it went unanswered for 2 months, and or the call dropped.I eventually got through, and they lady who took my call said that the billing department would call me in 4 days. That was 2 weeks ago. I sent numerous emails and agin they have requested me to give them my confidential details via non secure email They are a complete joke. I have now requested a letter of deadlock and am taking this to the ombudsman.