Xfinity Wifi Doesn't Disable

I disabled my Xfinity Wifi a few months back but Xfinity wifi continued to show up on my phone. I assumed it was a neighbors but last night I tried unplugged my router and everything else and the Xfinity Wifi went away.  I use a router where you can turn the wifi on/off - I never have it on.  How can I keep my router off but stop the Xfinity Wifi?