MTN Retentions

MTN Retentions worst experience ever, I am trying to cancel my data contract for the past 2 months with no luck. The usual response is that their system is down at the moment. Do they even have a system? but they can deduct from your bank account on time. They keep escalating this apparent problem to IT but I dont get any response or solution. MTN service is the worse and I wont ever recommend MTN to anyone. I am not sure how they can still be in business with such awful service.