Does anyone know how to combine Xfinity Mobile account and Internet Account

Hi so here is the situation. My service was disconnected due to payment failure (CC expired and I forgot to update) and so went to a store opened a new account and got internet again at my apartment. My xfinity mobile account had an updated CC. However now I received an email stating i will be charged 20 dollars per month because i don't have xfinity internet. How do I tie my mobile account to my new comcast internet account? Any help would be much appreciated.