ANSWER:

You have done your job.

As long as the true message has been conveyed to them, they don’t have an excuse anymore. 

Keep making dua for their guidance. 

QUESTION: I have heard of committing shirk due to ignorance can be excused and the knowledge is with Allah to know if a person is truly ignorant or has understood but rejects it. I explained shirk to my parents but they do not believe it is shirk to ask highly regarded people (who are not alive anymore) such as the ahlul bayt for help. I do not know if they die would they be excused?