MTN once again disappoints!

Contract No. A***. I wanted to do an upgrade today. After being told repeatedly by MTN that I do not exist, my cellphone has been discontinued and I am no longer a client of theirs, I drove around from cellphone shop to bank to try and prove that I still continue to pay my account and receive airtime every month, I was eventually told that I have been migrated to a system within MTN that nobody can work on. How does that work? How does MTN migrate one, to a system nobody works on and everyone tells you, you do not exist. I am feeling extremely frustrated.