IMO, I would steer clear of any negative postings towards any one or any business. You just dont want the forum to get a bad name. keep it alll positive and recomend the guys that are genuine and ignore the rest.
If you think you must, here is some info on the appropriate channels to have your complaint dealt with:
List of all State Department of Fair Traiding offices
http://www.complaintline.com.au/consumeraffairs.html
If he is willing to refund your money in full then the Fair Trading Department will drop the complaint.
I would just get your money back and ignore the moron. There is no excuse for bad behavior towards customers. However there is always two sides to every story.
Just my two cents worth.
Cheers,
Rob