MTN migration to prepaid is the worst experience ever!!

I cancelled my contract as I was due for an upgrade but didn't want a contract with MTN anymore. The same day I got migrated, all my calls and sms services were barred. I couldn't send or receive calls and smses and I couldn't even deactivate these barring services with their assistance over the phone. It's nonsense that migration to prepaid means I can have no calls or any form of communication using the SIM. To top things off, they didn't inform me beforehand that I should expect such yet the call centre was demeaning when I kept telling her it does not make sense that they barred my services.