Mondo has hijacked my MTN account - MTN not help.

Mondo has stop me from upgrading my account with MTN. They have had my account locked so I cannot do an upgrade. They do not work on weekends, I was on the phone with them on Thursday for an hour and was promised the would unblock the phone. The have really misled me totally. MTN cannot/will not do anything to help their customer of 20 years+. Time to move to a company that help me.