Last Bread Money deducted without explanation

I have formally sent a complaint to MTN who responded with a Ref number (***) indicating that I would have a response within 24 hours. Since then - radio silence. I even tried to reach out via LinkedIn - nothing. Since the death of my father, we are struggling with my mother's contract and two months in a row, MTN has unexplainably deducted last bread money from her account. Poor, poor customer service. Quick to sell. Terrible to engage with.