I don't want to spend time with my nephews because they kick me, hit me and throw toys at me and constantly try and put me down
Are you frustrated by this behavior?
I'm getting pretty tired of them
It sounds like your nephews are somewhat violent which is not right. Have you tried talking to their parents to see if you can find a solution together? It seems like they need to teach their kids gentleness and respect for others.
I'm not going to take time to talk about this with them.
I don't understand why you wouldn't talk about it with their parents. Don't you want the situation to improve, and your nephews to learn to interact with others in healthier ways? Simply refusing to have anything to do with them doesn't really teach them how to do that.