How can I sue or make a complaint against a school district/superintendent for what I believe has been excessve punishment and harassment

You should ask for a meeting with the admnistration.  If your child has a disability, the staff has to provide you with a statement that says the discipline is not a result of the child's disability (for example - a child with Tourettes cannot be punished for yelling out in class).  Get a record of what punishments are levied in the school and see if that applied to your child is consistent with others.