I don't know what the job situation in Australia is like, but here in the US, they probably would have gotten several hundred applications in those three days, so they would have decided they already had enough candidates to look over to decide who gets called for an interview. They almost certainly won't call you over a weekend, and if they decide other candidates would be a better fit for the openings, it's likely you won't hear anything back from them at all.
If they don't choose you, you may get a form e-mail from a do-not-reply address stating they have decided they will not move forward with you and wishing you "good luck with with your career search" or some other such pablum, which, speaking for myself, grates to no end, kind of like a cop telling you have a nice day after writing you a ticket for a couple of hundred dollars. At least here in the US, the system for jobs like these is set up to make it as difficult as possible to follow up with a person who can actually make a decision about who will be hired, at least until someone picks you for an interview.
My advice - keep looking for other opportunities, apply for anything you can find that you think you can do and pays you what you need. If you haven't heard anything from these people in a couple of weeks or so, I'd say it's safe to assume you won't, and of course you won't be getting the job. Keep as many irons in the fire as you can manage, and try not to get too discouraged when people don't even bother to call you back. This last is much more easily said than done, however.