Hi gonepeggin,
Welcome to CrowdSupport
Whilst we aren't able to assist with troubleshooting here via CrowdSupport, there are a few self-help tools you can use.
With any interruption you experience you any of your Telstra services, always check our Service Status page at: http://tel.st/6x6a. Here we list all known interruptions (outages or maintenance works) along with an estimated restoration time, when available.
Further from this, for all NBN technical support concerns, a number to save for the future would be NBN Assurance direct contact at 1800 834 273