MTN allowed a number that i have been using for more than 20years to be sim swapped

On the 22/09/2021 my phone lost network , when i tried calling MTN as usual i couldn't get through so i assumed there was a network issue. When i called again i was advised that a swim swap was done on my number and cannot be reversed because its been over 24hours. I am livid/Angry/****ed/annoyed right now because how can a sim swap be done on my number that i have been using for more than 20years by a random person and MTN allows it ??? like really ?? I have my BANKING and soo many other things i am doing with this number !!!!!!!! That means that when we are using MTN we are not secured at all if ********** can do as they please. How did they get my information for starters in order for them to do the SIM SWAP because last time i checked i used to get sms's notifying me that a sim swap is about to happen but this time nothing at all! MTN i need my number back ASAP before seek legal advise and take this to all the papers and twitter and every other social media so that people can be aware that we are not safe with MTN at all. My number is ***. You need to sort this out because i am now stuck and totally stuck and sooo angry.