Those that should protect your children the most while they are at school are the teachers and administrators. I'm so sorry you have to go through this right now. Bullying is hard for both the kids involved, and their parents. It's up to the school administration to decide what the appropriate punishment should be if it's found out that a teacher/coach has engaged in bullying.
Most schools have anti-bullying policies. Ask the school secretary for a copy of that. Next, try to approach the teacher/coach about your concerns. If they don't give you the response you're looking for then it may be time to take your concerns to the principal. Take concrete examples of what your daughter has experienced to share with the principal. Ask the principal if the school has a zero-tolerance policy regarding bullying, and ask what action will be taken to make sure your child has a safe learning environment everyday.