Failure to cancel contract as promised

25/08/2015 I called MTN 808 number to cancel contract which was due to expire 26/09/2015 (Ref ***). In October 2015 I realized that the data was loaded and I called on 05/10/2015 to enquire (ref ***) and was promised it will be cancelled within 72 hours. 15/10/2015 I called again (Ref ***) same promise, nothing happened. 26/10/2015 called (Ref ***) and I was told that an upgrade was app**** for in one of the MTN stores and I said I did not apply and I was told to submit an affidavit, which I initially refused to do because I felt that they should have sorted out this issue long time before this become so complicated. 16/11/2015 I submitted an affidavit (ref ***4) and when I followed up on 26/11/2015 I was told by Keitumetse that ID copy is outstanding which I e-mailed immediately and that was the last I heard from Keitumetse and did not respond to my e-mails and so is the call centre. 01 Feb 2016 I spoke to Zanele Radebe who said there is no affidavit registered on the system and I again mailed her the copy of my ID and the affidavit. To date I'm billed R755 per month for the phone that was not delivered to me please help.