Does MTN not check numbers?

Since getting my contract at the end of September 2025, I am bombarded on a daily basis by debt collection agencies looking for Nolwazi Mkwa****. I am assuming she was the previous user of this number. Now it begs the question, if this is RICA'd on my name, why do I get calls, and SMS notifications about all of her outstanding debt? How is this ethical? And if other agencies don't know the difference between myself and this other person, then does MTN?

Getting this contract seems to have been a massive mistake.