Non cancellation of Contracts

We (a company not an individual) requested 13 portable data usage contracts to be cancelled with MTN in April this year. After numerous back and forth they still had not cancelled them in October. I eventually went in to the MTN office in Umhlanga where they took all the paperwork again and advised they would cancel. We were then told that 4 of these contracts could not be cancelled as they were recently upgraded in September 2015 in GAUTENG!!! We are solely based in Durban therefore this was impossible. Clearly there was a ********** upgrade done somehow and we are still being charged for something we wanted cancelled ages ago. They still cannot tell us what store or consultant did this upgrade or cannot back it up with any documentation to show who upgraded it. Plus it was upgraded to the highest most expensive contracts you can have, hence a major increase in premium. It is December now and we are still having major debit orders coming off our account. Whereby still not 1 number has been cancelled. To add to this the staff we have been dealing with are being completely unhelpful and we need to obtain an affidavit for an error that was made by their staff.