Poor Service and no support

Last week I realized that I'm not receiving any calls. I can still phone my contacts, but not any MTN number 135 or receive calls. I logged the incident with MTN via Facebook. REQ***. Saturday I visited my local MTN store, but to no avail. Another ticket logged. Every time I enquire the feedback is that they are still investigating. After a week, my loyalty to my company is being questioned, due to me being unavailable. MTN refuse to assist or escalate. Been a loyal client for 22 years. Sending email is also useless.