Constant Badgering Me for My Mobile Number

How I can I get you, COMCAST, to stop badgering me at every moment to provide "my mobile number" because, you see, I HAVE NO MOBILE PHONE.  I have never had one, and I never will.  So does this mean that every time I sign in till forever that I will get that pop up screen asking me to provide my non-existant mobile number???  Is there no recourse?  Perhaps I should try putting in any combination of numbers, will that get it to stop?  If I enter 12345678990 as a mobile number will that work?  I've been hesitant to do that because I fear then that if I find myself unable to sign in, then COMCAST will believe that's my mobile number and set it so I need that in order to recover my account.

DO YOU PEOPLE NOT UNDERSTAND THAT NOT EVERY HUMAN BEING ON THIS PLANET OWNS A SMART PHONE??"?????????