Welcome to the community!
I'd love to help and see what causes the slow connection on your service.
Have you tried running speed tests on desktop/laptop connected via LAN/Ethernet Cable?
If yes, kindly post it on this thead also PM me your account details (username/customer ID or contact number associated with the account).
The srtock standard "cut & paste", next it will be it's Telstra's problem with their cables, then you get told can't be fixed you can leave TPG if you wish, ahhhhh,other ISP's don;thave the issue funny enough