@Tutty1986 This is not a direct Optus Support point, it is a Public Forum. This a post I made to a similar query.
have you checked for reported outages?
https://www.optus.com.au/about/network/service-status click on outages, Fixed Outages for NBN.
If there are no reported outages, here is a link to some troubleshooting
If there are no reported outages and the troubleshooting doesn't help you can message Optus Support via the My Optus app(Preferred), Facebook or Twitter. If you use Facebook or Twitter include in the message you do not have access to the My Optus app. You can try calling 133937 ignore the prompt to Press 1 and wait for the Options. I have read reports the waiting times on the phone are a long time.