No care and no clue

Applying for a business contract but MTN declining saying my number is flagged as "legal", one consultant says its takes 48 hrs, the other says 72hours, the last one now says 7 days, its seems MTN doesn't practice transparency and honesty, all I need to know why my number is flagged as "legal" and what is the way forward, if they dont want my number on their network then its fine, I can always port.