I'd still call and ask to MEET with a prosecutor. The prosecutor DOES have the power to (a) file charges themselves or (b) direct the police to do so. The advocate isn't a lawyer. She is probably speaking of what she knows to be the general practice. When I was a prosecutor we routinely corrected errors made by the police in not charging or undercharging.
At this point, it's the ADVOCATE who has told you "no," not the prosecutor. Even if the advocate works for the prosecutor's office, she doesn't make the decisions FOR the prosecutor. I'd call the prosecutor's office directly and make an appointment.