Good day @cfwschung,
Welcome to TPG Community!
The standard time frame of the NBN installation is within 2 to 30 working days.
For NBN HFC technology, requires an NBN Box for the service to work since we are going to use the existing coaxial cable in the area and not the copper wire that's why the phone line will not work anymore.
I am aware that you were able to speak with our Service delivery team and they have requested for an NBN technician to install the box for us to provide you the service. Further updates with the technician schedule will be given by them.
Should you require any assistance, please let us know.