Zyxel cannot connect to internet

Hi, my old modem (hauwei) had some problem. The T mobile guy came to help today. He provided a new modem (Zyxel T50) and replaced it. However, even the wifi is working okay, it cannot connect to the internet (red light).
He told me that I have to wait 2 hours to activate the internet, it has been more than two hours, I still cannot connect to internet. It is really frustrating. Is there anything I can do to get the internet I paid for?
Maybe need to release the old MAC address?
Thanks