xf1 gateway does not work with wifi or ethernet

Received xf1 gateway and it looked previously used with marks on it.  

Personal cable modem and routers working no issue.

Trying XF1 for unlimited data, plan to have this be a  pass-through not sure why xfinity wants me to use their hardware at $15/month for unlimited vs my own hardware for $30/month.

Use Xfinity app and the XF1 setup and said running no issues. 
* Ethernet never provided and ip address

* Wifi connected, but stated no internet connection

Spent over 2 hours with support and was told to take to Xfinity store and ask for replacement.    

Will try a new one and keep you posted.   However, what a waste to resources and time. when I could just pay $15/month for unlimited and use my own hardware.