Won't Cancel my contracts

I have TWO contacts with MTN that have both ended on 15 November 2015. I promptly called 808 on 16 Nov to request cancellation. Call was pleasant and I was confident that my request was being dealt with. I was even CC'd on an email to their retention's department to expedite my request. Was also informed that i would be notified by SMS once the migration to pre paid was completed. Having not received any feedback i called 808 again on 27 Nov and was informed that my request could only completed once my final invoices were paid which would be 1 Dec debit order. Once again nothing further regarding my cancellation i called 808, only this time i was informed that there was an unpaid invoice of Sept 2015 that was holding up the request. Confused and irritated i request a month my month break down of all invoices for 2015 vs what they collected via debit order from my bank account.....STILL WAITING!!!