Two things - were your K20 and lens purchased here through legimate channels, or were they imported?
If they were purchased here, remember that you have recourse against the RETAILER via the Consumer Guarantees Act. The retailer must fix things for you, they can't fob you off onto the distributor.
The second thing is that from what I've heard it can be highly dependant on who you get down there. I've stood by and listened in frustation to a camera salesman on the phone trying to find out whether they had stock of something (DA 40mm), and they couldn't even be bothered going and checking for him.
A thought which just crossed my mind - perhaps you could get an international warranty and try getting the australian agents to fix it, as other members have mentioned.