Welcome to the Community!
We tried to search for your account using your community details to no avail.
We'd like to look into your account for us to provide the correct information.
By the way, if you have an NBN service with us. The settings of the bundled VoIP of it is saved in the firmware of the given modem/router. You just need to connect a regular handset to the designated phone port on the back of the modem and the service will work.
You may send me a PM with your TPG username or customer ID number to assist you accordingly.