Welcome to the Community!
This is a rare case as it should not happen. We tried to search for your account using your community details to no avail.
Have you tried to factory reset the modem/router yourself? If not, please press and hold the reset button for 30 seconds then reconfigure it. Observe the device and let us know if the issue recur.
You may send me a PM with your TPG username or customer ID number to assist you accordingly.