MTN Disappoints

I am frustrated with the service at MTN. I had to go to the physical store twice and phoned the call center 6 times to get the problem sorted and still no joy. Every time I get promised that a manager will call me and still no feedback. I have not been able to receive calls on my MTN business contract phone for almost a week now. I can make calls but none of my clients can call me. They reset my number, it works for about ah hour and then back to square one. I requested to speak to a manager but it is impossible to move past the call center agents.