Before your contract is due, make sure you get the tax witholding statement from your company/school. Any individual who intends to leave Taiwan in the interim of the year, should file his income tax return 1 (one) week before his departure.
You need to have a Taiwanese friend to be your guarantor (not sure if this is still applicable, it happened to a friend of mine with similar case), and this person will receive the tax refund check, which is under your name. Assuming you have a bank account in Taiwan, your friend will cash the check to your account, and the bank will close your account and wire all your balance to your account in Australia. You need to inform the bank that you are leaving Taiwan and that a friend of yours will cash your tax return check for you sometimes later. You might need to fill out the “Power of Attorney” form provided by the bank.
Hope this helps.