There are Xfinity stores that accept payments. You can call 800-XFINITY or 800-COMCAST. You can log in to My Xfinity web site and pay/set up payment there. You can use the Xfinity My Account mobile app to make payment. There's the mail-to address printed on your bill (paper or viewable on-line) that you could send your payment. Just how do you want to pay it?