iPhone activation - error message on Xfinity's website

I am trying to activate a new iPhone, and I will be using my cell phone number from a different carrier. But when I go to xfinitymobile.com/activate, I get an error message that says "Something Went Wrong." The website is not allowing me to click on anything after signing in other than the tabs in my account, but I cannot do anything on those pages. If I go to "Activity," for example, it says "We're having trouble retrieving your data. Refresh the page or check back in a few minutes to try again." I have tried several times and from several different devices. I have also cleared my browser history. And I have tried shutting off and restarting my new iPhone several times.

Please help!