Failing to convert from MTN contract to Prepaid

I took out a MTN contract through Mobi Warehouse, when the contract period ended, Mobi Warehouse/ MTN failed to convert my number back to prepaid, which resulted to my number being deactivated from MTN as from 06 June 2019, without consulting me.I told Mobi Warehouse from the onset that I don't want a new number, as I had that number for all my life, now I am being sent from pillar to post in an attempt to activate my number. I am so desperate to get my number ( ***) back, as I am unreachable now, all my life is on standstill.