Welcome to the Community @loongtong2010
For customers experiencing any issues with their service, we recommend the best thing to do first is check if there's an outage affecting the network.
Check our Service Status at http://www.tpg.com.au/servicestatus for any known outages.
If you're on NBN, we have created this article that can guide you on How to Check for NBN Network Outage
If there are no known outages in your area, we recommend having a read of these community articles, which may help resolve your issue:
We understand that your case was escalated to our Engineering team for further testing, since there's no fault within the NBN network. An assigned Engineer will be in touch with you via SMS or phone call for further updates.