I don't think you will get a rebate hun, sorry.
If you're pay your tax in your salary (PAYG), then it should be calculated weekly or monthly, so whatever time of the year it is, you'll have paid the correct amount so far.
Basically, I've been told that there is a graph-type thing for every tax bracket, and you can look at any time of the year to see how much tax you should have paid by then. Your employer should have used that to work out your tax every payday.
Sorry! Hope I'm wrong!
