I have checked your with nbn and noted that they just completed your order. so can you tell about your set up. Make sure nothing else connected to any other socket except modem.
How many socket you have in your house?
where modem is connected?
which status lights of router are ON or flashing?
see below link for set up.
Based on nbn they have completed order however i haven't seen your modem up so i am going to create ticket for engineer to check with nbn. your ticket reference number 59581776 so TPG will also update to you as well.
In case if you see any other socket then try that one as well, because based on nbn test its saying modem is not connected, IF DSL become stable, let me know so i can also help you.