Problems with my children's grandparents. (AP mom).?

You did the right thing by stopping contact. An uncaring grandparent does more mental damage to a child then no grandparents. Its their loss. Kids are wondwrfully adaptive and will do fine without them. If your parents miss them or get offended, who cares? Selfish people think so much about themselves that another person thinking about them is just too much attention for one person.