Sure, there is, but you can't downgrade on line (if that's what you were trying to do). You'll need to call. But it's certainly doable; I dropped back to internet only some time back.
Hi jnagy8, I can assist you with downgrading your services to internet only. Can you please send me a private message with your full name, street address, and account number by clicking on my name (ComcastAmir) and then "private message me"?