MTN allowing RMCS to take over people's numbers

My mom (age 72) was using the number everyday for nearly 20 years. It was her main number that she used everyday and it suddenly stopped working. MTN Polokwane told her that her number was taken by a company called RMCS Pty Ltd. How? They couldn't explain. Instead of assisting her they told her to go to Hello Peter. We found the company and emailed them, their response was that we must go to MTN to RICA the number. We called MTN and were told that the number is now under contract. We suspect that it could be an attempt at ID *****.