It might be an idea to wait for a reply to your second email! In general if you quote an applicable CAO, CAR, or part of the act, you will probably get a favourable result.
If not, you might try the 'Commonwealth Ombudsman', or an Aviation Solicitor. I don't know how much help they would be, but CASA may back down if threatened with legal action, just be sure first that your interpretation is correct!
PS: Wanna give us a hint what it was about?
