Welcome to the Community @werrinw
For customers having issues with their Phone service, your may check our article: Troubleshooting No Dial Tone - TPG Home Phone/Voice Service for troubleshooting.
If the dial tone is still not heard, then you might need to factory reset the modem/router by pressing the 'Reset Button' on the back of the modem for 30 seconds. Doing this, the settings that you've personalised before (WiFi name and password, etc) will go back to default, which you may setup again.
The modem will automatically connect to the internet, but if the internet is still not working then you may check the configuration with the help of our article: How to set up your TP-Link VR1600v modem
Let us know how it goes.