Lancet keeps terrorizing elderly widow

My stepfather was hospitalized in October 2024 and subsequently passed away on 24 October 2024. While he was hospitalized Mauff AC & Partners from Lancet provided a service to him. His medical aid did not cover all the costs and after his passing my mother keeps getting threatening communication from this doctor's office. They were married outside community of property. We submitted all the necessary documentation on several occasions, but they still threaten her with legal action. It is now to a point where they are plainly harassing and elderly widow. Every time we call the office to again inform them of his passing and every time they act as if they have no idea that we submitted all the necessary documents. All the other providers made a note and stopped with communication. It is only Mauff AC & Partners' office that continues to threaten her.

There is no legal basis for their threats as they were married OUTSIDE community of property, and the debt died with my stepfather. My poor mother has to start the grieving process all over every time they threaten her. This is getting to a point where it borders on harassment.