What is the ruling of Islamic law regarding a father who has neglected his family and whose financial and social conditions have deteriorated because of a woman whom some believe has bewitched him, and what should the son do about this?

It is impermissible for a father to neglect those whom Allah has entrusted to his care, for he is responsible for the financial support of his wife and incapable children, and for dealing justly between wives in terms of lodging and sustenance. If his relationship with a woman is forbidden, he must repent. The eldest brother should assume responsibility towards his mother and sisters when the father abandons them, and advise his father or seek assistance from someone who can advise him, and increase in supplication for him, and perform ruqya (exorcism) on him for magic if that is deemed likely.