So,, according to the US Dept of Education:

>Parents or eligible students have the right to request that a school correct records which they believe to be inaccurate or misleading. If the school decides not to amend the record, the parent or eligible student then has the right to a formal hearing. After the hearing, if the school still decides not to amend the record, the parent or eligible student has the right to place a statement with the record setting forth his or her view about the contested information.

You may have to go nuclear on this. cc the superintendent, registrar, etc and request the school district's FERPA policy for your review. I would summarize the date and times that you spoke with whoever you spoke with, and what they stated (ie, they stated it was illegal, you asked under what policy, and they hung up on you). Basically create a record of communication "paper trail". Keep it polite and factual.