What do I do with my 16 year old son that isn’t doing his homework?

He just says he isn’t doing homework anymore. No reason, no why. He won’t answer us about what we can do better for him. He refuses to go to therapy. Refuses to talk to anyone. Even though we buy him lots of stuff that he wants (books, Kombucha brewing stuff), he won’t get good grades anymore. We set expectations and he broke them. We have threatened punishments if he continues and he doesn’t seem to care. When we follow through punishments he just goes on without what we took away. Can anyone help us?P.S. We have moved to 3 different places 4 different times in our lives if that makes a difference. via /r/Parenting https://ift.tt/2oIRnN8