Schools need to inform in handbooks of their policy, and parents need to read and be familiar with, the proper protocol in handling concerns. This is usually dealing directly with the teacher involved with whatever concern.
I see some go to the principal or the superintendent and bypass the teacher. Then the teacher remains uninformed and cannot deal with it until hearing through a third party.
Teachers can try to foster communication from the start, covering the strengths and concerns about the child. It takes two to make it work. Offering a positive attitude and genuine appreciation for their efforts often goes a long way in a beneficial relationship. It is frustrating when the process falters.
I also realized that parents undergo the same frustration with some teachers in trying to handle their end with their child's teachers. I do my best to accommodate the parents and their child. It takes more and more time each year. It is worth it if the end results are productive and all individuals make an attempt to see things from another view of the world by being open-minded.