I'd think about going to the neighbor and show them how to opt out of the public wifi.
When you connect, do you get any services, like browsing?
If you or anyone ever logged in to a comcast wifi spot, then the login is stored on your phone.
This page is long and rambling, but interesting. It mentions wifi analyzer and other things. Perhaps you can find a way to make your signal better, maybe by placing it on another channel. Or reposition the wireless so it has better coverage of your location.
Comcast XFINITY WiFi: Just say no | Computerworld
Have you tried unchecking Network notification? That should be in Wi-Fi settings.