The importer isn't me btw
I can pretty much guarantee I know who it is if it has been complied interstate rather than here...
Freshly imported cars aren't required to be serviced when they arrive here, just meet ADRs. The work that is done will normally be written on the Consumer Information Notice which I'm presuming you don't have seeing it was registered here first by the importer.
To put it bluntly, once it's registered in Australia, it can and will be as roadworthy or unroadworthy as any other car already here - in other words, it's buyer beware if you buy something with dodgy brakes, tyres etc. Once it is registered, the workshop can and will officially wash their hands of it, as they can claim parts were switched after it was registered.
If your seller also happened to be a car dealer, then that's a different story - you'd have grounds for taking it up with the Office of Consumer Affairs if they don't make the necessary repairs, even on vehicles supposedly sold privately.