Unable to cancel contract

I have been trying since mid-April 2015 to cancel a data contract with MTN. I made many calls to the call centre, sent them a number of emails and lodged complaint on [URL Removed] (20 May 2015). Despite MTN replying to my Hellopeter complaint that they would contact me, they did not. Now, at last MTN has rep**** to my email of 30 April and they state that the notice period is 30 to 90 days after I complete the form they sent on 15 June during which time they will continue to charge me for the subscription. The contract was for two years and has long expired.<br> <br> MTN: I consider notice to have been provided on 30 April - you have acknowledged receipt of this email. I demand a refund of the money you deducted from my bank account for May and June.<br> <br> I will take this up with the National Consumer Commission if you do not refund me.<br> <br> MTN Ref numbers: ***, *** and ***.<br> <br> I strongly advise anyone reading this not to do business with MTN.