Number wrongfully disabled

I cancelled my contract as of the 08.08.2018. It was supposed to be migrated to prepaid. The number was permanently deactivated. I have been calling since the 8th and no one is helping me to get the number back. I am just being put through from one person to the next. I have used up all my airtime calling as my cell c simcard is not registered on your network now. I was told to buy a new simcard and they would reactivate the number. I have done this but no one can help me to get the number activated again. Keep getting told that I am at the wrong department, they put me through somewhere else then that person tells me to go back to cancellations, cancellations tells me they cant help me. The number is used for business purposes. I need it back URGENTLY. Can someone please help me???