Welcome to the Community!
Did you test the speed via WiFi or Wired connection? Do you have the TPG provided modem/router or you are under the NBN BYO plan?
You may check these articles that may help you with the troubleshooting:
Slow speed issue
Wireless Channel on your modem - what is it and why should I change it?
Easy Steps to Improve Wi-Fi Connection In Your Home
Please send us a private message with your TPG username or customer ID in order for us to assist you accordingly.
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