Yeh dude jump on defencejobs.gov.au. You cant join as a pilot as an undergraduate. If you want to do a degree and join as a pilot it must be through ADFA, or you can try direct entry. Dont listen to everyone who says its to hard to get DEO at 18 just make sure you do lots of leadership at school ie. school captain, sports captain, volunteer your time things like that and you will be fine at 18.
Dont forget that 2 unit maths is the minimum and although physics isnt required it is good and does help.
Also the number is 13 19 01 for Defence Force Recruiting. 13 19 02 is actually the number for the Candidate Resource Management Centre which is who you speak to once you have actually become an applicant.
And another correction to someones previous post you dont need to be 18 to join the ADF as a pilot. The minimum age at day of appointment is 17 and you can apply whilst your still in school at the minimum age of 16 1/2.