We (Europe) often have a 2 year warranty on things like this. Checking what warranty Australia has would be the first step...
And yes, I would certainly expect more than 2 years out of engine-mounts.
I can't rule out it being a 'customer is dumb enough to believe our crap' scam.
I've had the control-arm on my Ford Mondeo replaced. Next time again, so I questioned them and they said, it must be the other one. Next visit it had once again have to be replaced (MOT/APK/yearly check fail-point). Then it turned out it was the third replacement on the same side as the other one was still the factory mounted version (rivitted instead of screwed).
So I got my money back (took over a year and spreading the story all over internet, but they eventually caved...)
Assuming it is a diesel... because I don't know if the petrol has vacuum mounts:
You can check the lower engine mount (the vacuum one) by taking the tube off at the vacuumvalve on the fron of the airbox, sucking on it and sealing it off with your tongue. If your tongue stays stuck to the tube for >10 seconds, there's not much of a leak. But they can also loose oil and that drops the engine slightly down. My rear one had a vacuum which was OK, but the engine still sat too low: there's a rubber stop that should have about 1cm clearance. Before changing the rear mount it was down to a few millimeters on mine. Some say it should even have 2cm clearance, but that sounds too much. This rubber stop is located under the airbox, but much further down, between the subframe and the gearbox.
Unfortunately it isn't shown on the subframe below:
