All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.
You are obliged to be kind and dutiful to him even though he has wronged you, and enjoin him to do good, and seek the help of whomever you think could influence him. If all of this is of no avail, then there is no harm on you either religiously speaking or in relation to the customs [of the society where you live].
Allaah Knows best.