Complaint! MTN system issues

I have been a client of MTN for years and I have 5 existing contracts with them. It's been a week now that I am trying to Upgrade one of my contracts and the deal cannot be done because of MTN system issues! The consultant had escalated this issue several times since last week and I have not received any positive feedback till today! Really disappointing service by MTN, really looking at moving all my contracts away from MTN!