MTN PRODUCT CANCELLATION - NON EXISTENT

It is with great sadness that i need to use this form of media to express my dissatisfaction with MTN. Needed to cancel a product (data package) that i took 2 years ago via telephone marketing (never again). I have been to various stores wanting to cancel this product as i have been retrenched and cannot afford it, to be told that i need to phone 135 cause you cannot do it in store. I do not seem to be able to get through to CANCELLATIONS. MTN has been debiting my account monthly which i have reversed charges due to poor customer service. Can someone from your CANCELLATIONS DEPARTMENT phone me on *** as a matter of urgency to avoid further action.