For customers experiencing any issues with their service, we recommend the best thing to do first is check if there's an outage.
Check our Service Status page for any known outages.
If you're on NBN, we have created this article that can guide you on How to Check for NBN Network Outage
You may also check this Community article related to the issue you are experiencing:
Troubleshooting No Dial Tone - TPG Home Phone/Voice Service
If the service still does not work, please send the TPG Customer ID or username via private message so we can assist you further.