Cancellation of Data Contract.

In February 2015, I took out a 3G contract on my existing account. With no coverage and no joy Ref no.***, I went to head office, in Roodepoort, and spoke to Shane Nel, and he got Ande Musimini so set up a booster at my premises, still no coverage after the booster, Ande said I'll have to cancel the line and go to the next service provider. He promised no cancellation fees and I had to sms the 3g line to him and deliver the ****le and sim card to a MTN store, I returned this to the Springs branch just after Easter weekend. 12/4/15 I checked my statement, and this line is still active. Ande said I should contact 808, to sort the accounts out, as he send the request 1/4/15. Numerous calls, holding the line up to 28 min at a time, Ref no.***, and still no joy. I went to Springs store, and they showed me this line is still active, and NO CANCELLATION has been processed. I have got no idea what to do from here, at this stage I want to put a stop order on this debit order, but this will have an effect on my voice line, as the two lines is on 1 account. I am really discussed in MTN, and will be moving my voice line when the upgrade is due.