I'd love to help. Have you tried to run speed test on a desktop/laptop connected via Ethernet/LAN Cable? If yes would it be possible for you to post the test result on this thread?
Have you done an isolation test and see if the speeds are still slow?
Disconnect every device (including any ADSL filters) from every telephone socket in your home and turn off any devices connected by Wi-Fi.
Plug your modem into the first phone socket without a filter using the shortest cable you have (less than 1 metre is ideal), connect one computer using an Ethernet cable and run a speed test or monitor your connection to see if dropouts continue. Note the results.
Try this also in any other phone sockets in your home and check the results to see if it makes a difference.
If this seems to have improved the quality or speed of your service, reconnect the other devices one at a time starting with any ADSL filters. Run a speed test or monitor for dropouts each time to determine if the issue resumes – if it does, the problem is probably with the device you've just connected.
If this process doesn't help to pinpoint a problem, the cause may be elsewhere – something in your home or office environment like a faulty modem or wiring, or possibly an issue in the network and to call TPG
