I have a Lumina phone which I have migrated from Telstra service to TPG provider. I would like to extend the length of time the phone rings however it appears this is provider specific. Therefore, the Telstra Lumia code to call is **61*101**seconds# up to 30 seconds rather than the 15 seconds given normally. Unfortunately TPG does not seem to accept this. The advice page states OPTUS has a code to dial and VODAPHONE has an online site. TPG seems to default to VODAPHONE, when I look at the details of my SIM, however I cannot identify where to extend the ringing.
I suggest trying: **61*121**30# or **61*+61414121000**30#
(Where the 30 is the number of seconds ring time you want).
Let me know if this works!
P.S:If wondering how to press a + on your phone keypad, I was able to do this on my iPhone by holding down the 0 key.