Mtn denies me my old number: Sim Swap

I was ****** of my mobile phone and have been using my mtn Sim card since 2013. Now I am trying to do a Sim swap since I cannot use the new number when everything I have is registered on this number. Mtn are making things difficult for me, I am blocked from the Sim swap process, tried to call the 135 number where I was told that their system is offline. Why do you rely on you questionnaires to determine whether I qualify for Sim swap. I urgently need my number back, my childrens school information is on the number. My bank and my access to my complex where I stay is on this number. People have used the same number for their reference on their CVS. Without this number, my life is stuck and MTN is refusing to help me.