Blocking my 77-year-old mothers phone after wiping out her data... disgusting bullies..

So, my 77-year-old mother phoned me on a different no. to tell me that her phone has been blocked and she cannot make any calls. On the 7th of Nov, she loaded 1gig of data, and on the morning of the 17th of Nov, she had 516 gigs left. the next minute she receives an SMS from MTN notifying her that she ran out of data and that her airtime has been blocked from being used for data. Now please explain to me how my 77-year-old mother must load data or airtime on a phone that has been blocked, not to mention the fact that you have ****** the 517 gigs from her - is this one of your tactics to ******* the elderly. Wow MTN, you will do well in a socialist environment