What is the ruling on dealing with elderly relatives who frequently curse and swear and do not accept advice?

It is incumbent upon a Muslim to offer sincere advice, for guidance is in Allah's hands alone. A Muslim is commanded to invite to the way of Allah with wisdom and good counsel. The obligation of enjoining good and forbidding evil should not be suspended on the pretext that advice is not accepted. The one who advises should repeat the advice and vary the means.