Cannot Change WiFi channel in Xfinity Router. Why???

My Xfinity Router will not let me change the channel. I have followed the instructions to go to the very useless Xfi web site, and it does not give the options the Embedded webpage provides for the router. I have many signals around me, many causing interference. I cannot change my neighbors router, so I need to change my router. If the router is not smart enough to find an open channel, I am, and can choose a clear channel, So why, WHY, wont this router allow me to change the channel... There has to be a work around, and if there is not, I will simply find a new internet service profider. So please give me solid answer, about changing the channel, I have setup Corporate networks with many kinds of routers, switches, and this is normally a simple task. Xfinity, you need to stop dummbing down everthing. some of us need these options... Thank to anyone that can help!