********** upgrade

Nasua mobile put thru an upgrade to a very expensive package despite my request to cancel contract when they went over to MTN. I have sent thru the documents so several different people in various departments but never get any feedback, on email I have loads of correspondence including affidavit and signed document from Nasua saying they won't upgrade me as well as certified I'd copy as request by MTN but now I have been handed over ??? Pathetic doesn't even begin to understand. call centres can't help you. Shops you walk onto can't help you. How much airtime have I already WASTED trying to get something out of this pathetic situation. I did NOT sign an upgrade. Why should I be liable for the crazy costs ? And the number is oit of use aswell ????? Where to now ?