Is it permissible to forsake a neighbor who physically assaulted the questioner's sister out of vengeance, and has not apologized for his action?

It is understood that if the injustice persists and the aggressor has not repented, then one may continue to boycott them. Similarly, if the boycott is due to a terrible crime, according to Sharia (definition), custom, and nature, which the soul cannot forget, even if the aggressor repents, then the boycott is permissible. However, if the injustice has ended, then the boycott is permissible for only three days, so that the soul may recover.