Bad service on MTN

I'm so furious with mtn I had contract with them via department of health,now when they were cancelling the contract they failing to put my number back on prepaid,my simcard has been deactivated now,no calls or msg for the past 6 days,bearing in mind this is my only primary number which I use for my accounts,banks,job application etc .I have calls their customer care went to the store,no one to help me solve my problem,MTn is the worst network ever I regret taking that contract with them