Meanwhile, all they can do is complain and strata sends notices to him.
No, they can pusue Notices to Comply through NCAT, seeking penalties and Tribunal orders. Following that, they can even take him to court for failure to obey Tribunal notices. Sending “warnings” and leaving it at that is a waste of time.
If there’s a problem, send a Notice To Comply on the official form. If the brat ignores it, they should apply to NCAT for the imposition of fines (you don’t need to go through the Fair Trading mediation process) then escalate it until the departure process is accelerated.
This has the double effect of dealing with the immediate problem and letting other residents know that by-law breaches will not be tolerated. Let me stress this one more time: unofficial written warnings are a waste of time. Notices to Comply are both a warning and the absolutely essential first step to having the problem fixed.
They are not a fine because OCs can’t impose fines or penalties, so those reluctant to take action can calm themselves.