CJ sorry to hear it buddy! This is garbage and not really something you like to see from SAU Traders (not blaming SAU in any fashion). Mate if you have there address it may almost be worth making the trip to go see them personally. I know I would. Its easy to avoid phone calls and emails but not so easy to avoid a face to face confrontation.
Heck if theres enough of you, you could organise a group to go see him along with Today Tonight.
If you havent already I wouldnt be sending a letter of intent to his email and mailing address, and if you get no reply then you may have no choice to but seek legal aid. Its not cheap I know, but you may have a chance of recovering your hard earned dollars.
All else fails sell the debt to some bikies.