School Violating Disability Rights

My son is a * yo 1st grader. He is autistic and has had a * plan in effect since the first team meeting on February *, *. His accommodations include preferential seating, extended time on tests and assignments, and small group for testing. Despite his accommodations, his teacher forces him to complete his assignments during recess at least *-* times a week. I was not aware this was happening on such a consistent basis until this week. She also claims that because of their age, she already offers accommodations to the class as a whole and doesn't feel like it's necessary to expand those to fit the needs of my son. He constantly gets minor incident reports for behavior that is a direct manifestation of his disability, i.e., fidgeting, "ignoring" directions, and noncompliance. To sum it up, it seems like he is getting punished because of his disability. Due to his overactivity and rigidness, my son was originally diagnosed with ADHD and Oppositional Defiant Disorder at the age of *. He took Tenex for 2 years to curb the overactivity, but the effects were adverse. He was lethargic most days and had low blood pressure. However, once he was referred to a behavioral pediatrician, the diagnosis changed to autism, and we subsequently stopped giving him the Tenex. I have provided his diagnosis letter to the school that explicitly states that he was misdiagnosed with ADHD. Despite this, his teacher, on multiple occasions, has attempted to undermine the autism diagnosis and urge me to put him on ADHD medication. I refused and maintained my support of the pediatrician's diagnosis. At our last meeting on March *, she even went as far to request that I provide the school with a doctor's note stating that he is not required to be on medication for his overactivity. It seems to be that his teachers aren't concerned about the adverse effects of the medicine, just as long as he stays quiet and still in class. My son is extremely intelligent, but he is borderline failing language arts and math. I would really like to keep a good working relationship with the school, but I'm not sure how to do that when his rights are being violated and his education is being jeopardized. Is the school's actions a violation of Section * of the Rehabilitation Act and/or FAPE? If so, how do I effectively communicate to his team that I will not budge on my son's rights to appropriate education? I have self-educated and feel reasonably comfortable presenting research, data, and laws to his team during * meetings.

They have said on multiple occasions that he doesn't even seem disabled or they'll mention that there are other kids more disabled than he is. Is this discrimination?