if they think the seclusion room is inappropriate discipline for their children's misbehavior.
Maybe the alternative is they can take off work and come deal with their misbehaved child themselves.
From my understanding, the children aren't placed in the rooms for convenience. It's for their behavior which is difficult to control in another fashion.
I realize that having a special needs is challenging, but I'm sure it's equally as challenging trying to provide an education to them. School isn't a magic pill for overcoming physical and mental special needs.
I would like to know in the parents' complaint, what are their suggestions and what do they do at home to deal with these issues.