Responsibility of agencies for families

Can anyone advise what recourse a family has in the following circumstances and does the mental health team caring for the man have a duty of care for the family? He is suffering from a manic relapse of a bilpolar illness. He has forced his wife and teenage son from their home and changed the locks rendering them homeless. He has had a mental health act assessments but despite ongoing harassment of his wife and very distressing online abuse it has been deemed not necessary to detain him for assessment and he is apparently engaging with services and taking medication.