MTN *****s my number

I have had my phone number with MTN for 20 years, suddenly on Saturday, 19 April 2025 my husband informed me he could not get hold of me, my phone was off. I tried to call him from my phone which gave a message that I got to go to my service provider, I was informed that my number was re-allocated and I can't have it back. I had the number for 20 years and this seriously impacts me, all my apps, everything is linked to this number, Why do I have to go through this whole change because they are not obligated to check if a number is active? Who can help? The staff at MTN just shrugs their shoulders, not their problem!!!