I cancelled my service two weeks ago and just billed again

After 45 minutes on the phone with an Xfinity rep, I finally got my service cancelled. I didn't see anything updated on the app or receive an email confirming this was completed. Today, I check again and still no change to my account and I have a notice of my next bill being due in June.

I need someone with Xfinity to verify my account is indeed cancelled and refund any overage in payments made.

My acct#: [Edited: "Personal Information"]