The problem with sending a message to the company to call the cops is that some tosser from the
PR department, or some local manager who does not want a scene or schedule disruption, may water down or even disregard the captain's instruction.
Having an internationally-recognised code that stopped short of requiring armed intervention but still triggered official action would remove any management indecision or interference.
In certain jurisdictions, banging off the hijack code for a relatively minor incident could have unintended consequences.
Not sure where you work but I do not believe a request as indicated would be ignored. Radio will do me fine thanks.
Please keep in mind this is in response to the suggestion of a new code for disruptive pax, not in any way a criticism of what happened as I don't know and therefore I'm not in a position to comment.