Deactivated sim card

i had a contract sim card with MTN *** which after the contract ended i changed to prepaid. i haven't used my sim card for a month + and MTN decided to deactivate my sim. i had everything registered in that number and now i am struggling. after realization that they deactivated i tried for about 2 weeks to get them to assist in getting my number back but nothing yet. a call was logged for me ref nr:*** and they promised my number will be activated in 24 hours but a week has passed and they keep sending me from pillar to post each time i call for feedback. clearly there is nothing "BHOZA/CHAMPION" about MTN service!!!