My apologies for the service disruption you've experienced.
From what I gathered, your service was affected by an NBN outage. It was reported by NBNCo at 12:42 AM AEDT yesterday (December 16) and has been declared resolved last night at 7:50PM AEDT. Based on the information provided by NBNCo, the downtime was caused by a 3rd party damage to a cable. Technicians from NBNCo had to repair the fiber cable which restored the services.
I can see that your modem has been up since 7:11PM AEDT last night. If you're still having trouble going online, feel free to leave a message.