MTN- DEAD END

I am really fed up with MTN, my boss has called through TWICE now to have his primary contact number changed (AS IT WAS AN MTN ERROR THAT IT IS NOW INCORRECT) The first call was made on the 16/08/2021 and then again on the 27/08/2021 for the same issue and we log on to check and it is still not sorted. Why is it such an issue? MTN easily changed it incorrectly on there own accord so easily, why cant they change it back just as easily.