Have you logged in to your account (NOT using the links in the email) to see if what is says is correct? Have you copied the message header info and forwarded it to firstname.lastname@example.org for investigation?
It's a phishing email, a scammer attempt to steal login and account information. If you check your email with Comcast's Xfinity Connect webmail, look for the XFINITY Verified Email logo next to any message that claims to be from Comcast/Xfinity (see https://www.xfinity.com/support/articles/comcast-verified-email).
Please edit your message to remove the email address and the phishing link. To edit, log in to the Forums and, while viewing your message, click Options, Edit Message.
Please see Comcast Email Phish or Legit? How to Tell (and rules for posting) for more information about identifying, reporting, and posting phishing emails. The article is somewhat out of date, but still useful.
Samples of recent phishing messages can be found at https://internetsecurity.xfinity.com/help/alerts/ under "Top Phishing Scams".