how to get charge removed for movie I did not rent

I received an email with subject: Here's your On Demand receipt. The email read: We hope you enjoyed the show! Thank you for your recent rental of Hairspray HD movie for $5.99

Knowing that I had not ordered any movies, I was suspicious of the invitation that said  "If you didn't make this purchase, please click here to chat with Xfinity Assistant" because when I clicked on it, it asked me sign in. I was already signed in. Couldn't look more phishy for an average senior adult trying to be online-wise.

I don't know how to navigate the xfinity website since most everything about any question simply points you to an article that doesn't seem to have anything to do with the issue. I have now spent two hours of my life that I will never get back trying to chase this down.  The fact that I have a work deadline to get done today but am concerned that this is a security issue that I need to get handled is not a good thing. 

HELP.