Mtn number deleted

My MTN cellphone number which I have for more than 10 years has suddenly been destroyed with notifying me. Now no one can get hold of, my number does not exist. I recently app**** online for grade 1, now the government will reply to a number that does not exist😞😭 I will not know which school my daughter has been accepted.

I went to an MTN shop and they explained that my number has been destroyed and there is no way to get it back. Can someone please assist. I need my cellphone number back