Step One: Get an Australian Netflix account.
Step Two: Download a VPN service to your device.
Step Three: Log into your Netflix Australia account, and change your location on your VPN app to US.
Step Four: Binge on all the shows you couldn't get on the Australian Netflix while you cry tears of joy.
You might say...
"But the US account is only $7.99 a month!!"
That would be $7.99 USD and don't forget conversion rates, and the international transaction fee you would have to pay.
Anyway, this way you can switch back to your Australian account and access all the Summer Heights High that you want.