Data buddles disappeared

I have been having problems with my MTN contract, from airtime disappearing from my cell phone to Mtn inability to fix my phone which was still under warrantee to poor customer services by their stuff and general unwillingness to help. I have expressed my complete dissatisfaction to them with this regard. Drawing closer to the expiry of my contract, I called MTN at least twice to inform them that I wanted to cancel my contract and I was assured that the contract s will be cancelled. On the 21st MTN loaded airtime on my cell phone, I called to query why, because I had already advised them of my intention to cancel. The lady, advised that there were no note on their file that I even called. I told her that I was not happy as I did call. I advised them that they must remove the airtime they added because I did not want to pay for it as my 24mon contract had expired. MTN the took all my Data including the 521MB that I had before I cancelled the contract. They put me on prepaid, so I could not contract the contract's department anymore, the155 did not give me an option to speak to someone. I am complaining because MTN took my Data that I had already paid for, this is ****************