I don't know how it works by you, but I would set social services on this family. They are very good around here at sending counselors to the school to talk to kids and then the parents find out usually from the child. When I was in 5th grade my ex-stepdad got counselors to come to school to talk to us on false claims of child abuse just to harass my mother. I think that if they did that the parents might straighten up a bit, of course they might immediately think about who called soc services.