turning off wifi with xFi gateway

I am trying to get a new internet plan that offers 200 Mbps download speed instead of the 75 that I currently have.  Although I have been told that the current router I'm renting will handle that speed, keeping it isn't an option in the automated order pathway.  The reason I don't want the new gateway, which would be the xFi, is that I use only ethernet, NOT wifi and I don't want it broadcasting in my environment.  I have to sit working too close to the router in my limited space.  On the page that describes the xFi, it gives instructions on how to turn off the wifi, but then below, in italics, says, but with the xFi, you can't disable the wifi. What????  Which is correct?