Xfinity App not showing WiFi and Services tabs after 4 days of using new XFi Gateway modem

This app has issues.  I am STILL not seeing the WiFi and Services tab 4 days after installing my new XFi Gateway.  I can't configure my network, change my password, anything.  This is after TWO in store visits where the Xfinity employee assured me that it would show up after no more than two days.  It's now FOUR days and the tabs are still not there.   All I see are the Overview and Account tab.

Also, the Overview app in the tab continues to say "Your bill is past due", which is NOT true, and the employee at the store confirmed that I'm not.  He said that it was just that the app was not properly synced.  How do I get it synced?!?

Finally, I have this XFi gateway on my main floor, but the computer and TP-Link smart switches in my basement are NOT successfully joining the network.  The signal appears to be too week.  They see the network, but fail to connect.  So my main computer can't use the Internet.  What do I need to do to get one of the Extender Pods so that I can use that computer and those devices?  Everything on my main floor is fine.  The upper floor is ok, though network speeds are slow (<200mbps even though I'm paying for a 600mbps plan).  But the basement coverage sucks.

HELP PLEASE!