Does the executer of my dad's death have to follow my dad's wishes without a Documented WILL

My father passed 8 years ago with no documented WILL just a written paper that he had wrote and gave to 4 of his children. The other 6 children were to get nothing because they abandoned thete father for 30 + years. No communication at all until he was on his death bed. He then made one of those kids executer of his death. My dad didnt have anything to leave to his 4 children that. He raised and that took care of him. But he did have a house that was to be sold and split 4 ways. He wanted 20,000 to go to myself and my other sister and 10,000 to my 2 brothers anything left went to his ther son witch is the executer. Within the 2nd year he did sell the house and myself and my sister reached out to him to make sure he was going to carry out my dads wishes and we were told to " never to contact him again that he is keeping the GD money because my dad owed him for the years they didn't have a relationship. Does he have to follow my dad's wishes witch was written down and given to him and