If I am able to show all elements of the offence, and not vexatious, then I have grounds for the CAN to be accepted.
Perhaps you can't.
Or perhaps, in your application, you didn't.
Even if you did get the manner and form of the draft Notice correct,
perhaps the Registrar believes that the facts and circumstances
that you provided in the application are not in themselves sufficient to ground a charge.
Further and in the alternative, even if you did show a factual basis for a specific charge,
perhaps you don't have (or did not include) sufficient
prima facie admissible evidence to show reasonable prospects of success
at proving whatever offence it is
beyond reasonable doubt.
Further and in the alternative, perhaps the Registrar has formed the view
that your problem is more in the nature of a civil dispute than an offence,
and that a private criminal proceeding is not the legal
machina that is
most likely to bring
you justice in
this case.