IDEA Sec. 300.506 covers your right to mediation.
Any time you are dealing with a public agency, there has to be a process by which to mediate complaints that follows a specific set of rules.
The State must pay for the cost of this mediation. They have a list of people who can act as mediators who are not employees of the school or local education agency or have any type of conflicting interests. They must choose from this list impartially (randomly or by rotation, for example).
They must also explain the benefits of mediation over litigation in a way you can understand easily.