Harassment

I am harassed by a person whose daughter keeps running away from home. My son was a friend of her. But she is adult and keep running away from home due to family issue. My son just happened to comfort her as a friend. But whenever her daughter runs away, we keep getting calls with threat. Even now, we were out of station and my son was with me and she again ran away from her home. And he filed a police complaint for this, though I do not have official verification for this. Supposedly somebody claiming to be from Kondhwa (Pune) called me. And we are travelling in West Bengal. What should we do. My son is still a minor.