Worst service ever MTN Brooklyn

Worst service I have ever experienced is from MTN Brooklyn Mall. In August I upgraded my contract, doing so the consultant at MTN made an error on my contact which leads to them suspending all outgoing facilities at least once a week since August mtn been promising me they are in the process of rectifying their error, 5months later I'm sitting with the same issues, I have tried phoning MTN head office but once some one eventually answers they hang up on me