The thing about behavioral therapy is that one size does not fit all. And yes, while it can be effective, it does not happen over night. The type of reward system you were suggested to use can work great for younger kids, but as the kids age – its not as effective. Your therapist needs to know it is not working and should then make adjustments. If the therapist can not make adjustments to this kind of “canned” approach, then I would look into other therapists. The other thing is that You need to be an active part in this therapy. Its what you do at home, how you react to him that is most important! For example there is a lot of material on the additudemag.com site that gives very practical ways to work with ADHD kids. A good example is this: https://www.additudemag.com/slideshows/anger-management-for-kids/?utm_source=eletter&utm_medium=email&utm_campaign=December
this is the kind of information you should be getting.