Call Aus Post and report it.. or go to the post office there is a complaint form.
The guys delivering packages are generally contractors to aus post, some areas have 3 or different contractors, some online deliver international express items, other international basic and local parcel mail air/truck east west...
Ive made a few complaints about one of the 3 drivers that comes to my place not even delivering the items, ive never had a issue since he walks up my driveway now.