How tough to be 10 and have school be a problem, then Mom is mad because school is a problem, Dad punishes you when you go see him, and you might lose sports. Two of my three sons have ADHD. They are not taking medicine although I wish the older one would to help with focus in school.
I got caught up in this same cycle until my oldest son told me that noone smiled at him at school except for the wonderful custodian. Then when he got off the bus, I was angry and frustrated because I'd had a call from the school. When I quit being mad, I started figuring out how to help him. It has been a long journey. We changed his diet, provided more outdoor play time, set limits for homework time (which made it more of a game) and discussed the school calls but did not impose additional consequences. I helped the teacher figure out that sticker charts were not helpful and that more time in the library was good. A wonderful teacher let him sit in a bean bag on the floor instead of at his desk when he was starting to be a distraction. And we made a chart for him to fill out on the teacher to help him figure out if she was happy or mad and why.
Not paying attention in school is not just your son's problem. He may learn better with some kinds of teaching than others. He may need more activity. He may have a reaction to food eaten at lunch time or even scented markers or the floor cleaner. You can be a huge part of his solution by being on his side and figuring out why things are so tough. My kids have auditory processing deficits. Although they are quick learners from books, they do not learn well from spoken speech. So they tune out or try to liven things up. Once they understood this about themselves, it was easier for them to behave.
Some kids have done as well with additional exercise and natural food diets as medication for ADD/ADHD. Your son needs help with school but instead of punishment, he might do better if you set a timer for an hour so he can finish his homework and anything he couldn't get done in class.
I've worked with the school so there are logical consequences to misbehavior (never loss of exercise time) like a working lunch. At our school, kids are sent to the counselor to fill out reflection papers. Parents shouldn't be expected or agree to make home life miserable just because the school is having a problem with your son. You are all working together to help him. Home should be as safe and loving and structured an environment as possible so he knows what to expect. He should have a healthy snack, time for homework, time to play outside, and time to rest. My boys do better with no video games or tv on school nights. They read because they want to but laying on sofas or in bed.
I really like Edward Hallowell's books on ADD. I was shocked to learn that I probably have ADD too. But I was lucky. I walked a mile and a half to school each morning, had natural food, and so many fewer distractions than our kids. Nonetheless, I remember the stress of being distracted or flaky or ditzy - there were many excuses. His books stress finding the gifts in each child.
Good luck. You can make a big difference in your son's life. My youngest at 10 has the same issues but is so much happier because we never got mad at him. He's had a few troubles at school with impulsive behavior but they handled it calmly and logically without making him feel like a bad person. We've been lucky with teachers who let him stand at his desk to work without saying a word. He doesn't get any negative attention for being active but is generally the one who is picked to run errands. He scrubbed the floors for a couple of lunch periods after some messy volcano making and brags about having this extra time with his funny teacher. He has no idea that the teacher is doing any of this to keep his mind and body active.
Some of his grades are worse than others. Instead of getting mad like I did with the oldest, we just follow the teacher's lead and say, "too bad for you." What do you think you could do differently? She has a "no excuses" policy for finishing work and doing a good job.
Sorry this is so long but I have a soft spot for the boys who get in trouble.