Thanks for contacting us with your parenting concern. It sounds like you have tried many strategies in hopes of getting your son to be successful at school. Hang in there and remember that parenting strategies often have to be modified to fit the needs of our children.
Perhaps delivering some rewards, as well as consequences throughout the school day, will help him realize what's acceptable and what's not acceptable. Consequences (both positive and negative) are most effective when they’re issued right after the negative or positive behavior. It's possible that waiting until he comes home to receive his reward or punishment is too long of a time span for him to connect it to his behaviors. To help modify this, talk with your school about how they may help implement your motivation system. They should be willing to work with you as they're just as frustrated with your son's behaviors as you.
Be as consistent as possible. Remember that change doesn't happen overnight and that your son will resist everything at first. Push through that resistance until you start to notice small changes in his behaviors. Set realistic expectations. Set a goal of one positive action a week rather than having positive days every day of the week. Praise him for even the smallest positive changes and stick with it. Your hard work and consistent training will pay off with changed behavior.