Account Error Messages

I'm unable to access parts of my Xfinity account. I have no problems signing in, but I keep getting error messages every time I try to go to Payments, Billing, or any page that has important account details. Most of the time, the error message is: "Something unexpected happened. Try refreshing the page. If this problem persists, please check back later." Whenever I attempt to make a payment, the message changes: "Sorry, this isn't working right now. Please return to My Account overview while we resolve the issue." I've refreshed and revisited these pages multiple times. Nothing changes.

Some have recommended clearing my browser cache or using a different browser. I tried doing both. The same errors appear no matter what browser I'm on (Safari, Firefox, and Google Chrome specifically).

I even tried using the Xfinity mobile app, but then this message pops up as soon as I sign in: "Access not Authorized. You signed in successfully, but you must be an Xfinity user to enjoy this service." 

...What is happening?? I just want to check my account/bills/etc. online, but the site has been preventing me from doing so. Can someone help fix this?