Hi Mom0405
Has anyone ever suggested applied behavior analysis (ABA)? It's commonly used for kids with autism but it applies to us all. You may want to seek out a board certified behavior analyst to conduct a functional behavior assessment (FBA). I stress this person needs to be board certified. A psychologist who is not board certified by the BACB is not qualified.
From the FBA you should learn what motivates and maintains your son's behavior. The behavior analyst should be able to help you with a specific plan to decrease non-compliance and replace it with a more appropriate reponse.
I had a FBA done on my son then 4 and having the same issues. The FBA really helped me understand why my son does what he does and how to handle him. Check out www.bacb.org - there's a registry of certified consultants and you may find some in your area.
I also like the book "1,2,3 Magic". It has some useful tips.
Goodluck. If you need more specifics on ABA - let me know.