Mtn and Rmc ********** sim swap

Mtn allowed RMC to do a ********** sim swap yesterday with my wife's number.. She has proof that this number is hers even the exact date and time she purchased the phone that was activated with specific number in 2012. Yesterday Rmc did a sim swap and mtn allowed it. We called mtn customer service and they tell us the specific number is a business number activated 2014.

So how can a specific number be activated 2012 via private perchase in a retail store than two years later activated as a business line. Why can't mtn track and see the number is active from 2012 which was prepaid.