Is it correct to boycott a person who commits incest with his underage daughters, using religion as a cover for his actions, especially since the Sharia forbids boycotting a Muslim for more than three days?

A man committing adultery with his mahārim (unmarriageable kin) is among the greatest abominations. The punishment for a father who commits adultery with his mahārim is stoning, due to his being a muḥṣan (married person) and having violated his mahārim. This father should be advised and convinced through available means, encouraged to perform Hajj or 'Umrah to distance him from his daughters, and efforts should be made to marry them off. If direct confrontation is not possible, he can be given books, fatwas, and tapes related to the subject. Abandoning him (social boycott) depends on the benefit and its potential impact: if it deters him, then abandon him; if it is not effective, then advice is preferable. The impact of abandonment varies with different environments. Abandonment is effective in committed Muslim communities but might push a Muslim in non-Muslim societies into the arms of disbelievers. A Muslim does not exit Islam due to any sin unless it is shirk (associating partners with God).