Below is a list of some troubleshooting techniques which will help you identify the source of the issue with your phone service.
1) Isolate your line to just one phone handset by removing all other devices e.g. modem, filter, other handsets, Foxtel, alarm, etc.
2) Test another phone cable between your handset and the phone socket on the wall.
3) Plug your phone handset into another socket if you have multiple phone sockets in your premises.
4) Test a second handset. If possible try a standard corded handset. A cordless phone base station with multiple satellite handsets will need the base station unplugged and a separate handset tested.
Should you need further assistance, feel free to search community for help or chat with us at https://www.tpg.com.au/support/contact/ and we'd be glad to assist you.