Pathetic support structure from callcentre

I have been overbilled on my account for two consecutive months already, tried calling callcentre and hold for 10 minutes only for the call to be dropped on EVERY occasion. My contract package is a *******, data is only refilled on the 3rd of every month and by the 7th I get 3 smses all at the same time saying, your are half through limit. You are approaching limit and you have exceeded your limit usage for the month. Here's the catch, I never turned my data on! How can something be used when it wasn't? Mtn is bunch of *******. I want my contract cancelled because proper documentation was not even received when I did my upgrade. I have not even received a copy of my contract and this upgrade was done in October 2014! Please advise how a contract is verified to be legit without a copy of I.d? On that grounds and lack of service, it's a null and void contract so contact me or I shall take this further than hellopeter.