MTN - unprofessional service

I have had disgusting service from MTN. A manager, Director cannot call you back, if a consultant, supervisor cannot assist you. I have been with MTN for over 25 years, and the service seems to be getting worse. I want to cancel all my contracts, as I find MTN extremely unprofessional and not helpful at all. However , not even this can done as I cannot get through to the relevant person. I have been on the phone for 5 days now, no resolve. Absolutely disgusting service.