MTN SA

I have been a customer at MTN for over 20 years. 18 Months ago I upgraded and since I have been having problems with the Network. I phone them every week with no luck. I'm working from home and my customers can't get hold of me, neither can I phone out, I phone 10 to 12 times before I get through. My phone has been diverted to my wife's phone to make sure my customers get hold of me, but that is costing us extra money. If we phone MTN they say they will report it or that they will ask the Manager to contact us, but that never happens.