We have likewise replied to your post here: https://community.tpg.com.au/t5/Broadband-Internet/Very-slow-upload-speed-on-ADSL2/m-p/25200#M10181
I would also recommend having a read on this Community article to improve the connection on your Wi-Fi:
Please don't hesitate to let us know should you require further assistance.
I'll repost your reply from other thread and continue here.
Welcome to the Community!
I managed to run remote test our end and it shows that the line speed you are currently getting is acceptable based on your distance from the exchange. It is ranging between 14-15Mbps respectively.
Were you able to perform any basic troubleshooting? Did you try testing the speed using wired or wireless connection?
If possible, have the speedtest done over wired connection preferably through a laptop and disconnect other device(s) so we would know the actual speed you are getting on your end.
Otherwise, let us know of your best contact time & number via private message so we can organise a call back to be made from our Technical Team for assistance.
I'm achieving the speeds you said for Download speed, but the upload speed remains zero.
I've tried with and without cable on 2 different laptops, I've tried uploading a single 50kb img to varying apps and websites, including Gmail, Telegram, Line, Skype, Discord, but am unable to upload to anything on either app or webpage.
As per the lady I spoke to suggestion, I've tried with a mobile phone for similar apps and failed.
For my laptops, I've done the following also.
Tried different TCP/IP and DNS settings (currently reverted to obtain automatically)
Gone through the modems internal settings to determine if anything looks out of the ordinary, etc
I've had my friend offer some support as well and go over settings (He was a senior domain architect for Telstra).
What sort of upload speeds were you able to obtain at your end? Is upload shaping enabled?
Thanks for the additional details. Our initial test result shows that the upload speed you're getting on the line is passing 1020/Kbps. The connection speed will only be throttled/shaped if you exceeded the Data Allocation based on your ADSL2+/NBN Plan.
This can be considered as isolated issue, we'd like to arrange a call from one of our Senior Technicians for further test and investigation.
Feel free to PM us your best contact number and preferred time.
In case you need a reference: How do I private message (PM)