Welcome to the Community!
I've searched for your account using your Community details and was able to find a match.
It appears your service is ADSL2+ with Home Phone. I just ran a remote line test and this shows no physical issue on the line.
I've noticed that you've ran the speed test via wireless connection. Have you tried connecting one of your device via Ethernet cable for testing purposes?
There’s some great tips on this topic here on TPG Community which should address this concern
Please visit these articles and let me know should you need further assistance.
Apologies for the trouble.
I do still recommend that we have one of our technicians give you a call to resolve your issue as your service may be affected by other factors.
Please let us know your best time and contact number via PM so I can get a technician to call you.
For your reference, please view this link on How do I private message (PM) in the community.