There is a charge for a purchase on 6/6/18 that I did not authorize. I do not rent movies on demand, I only watch free movies. If I need to setup a pin or passcode/password to prevent this from happening again, please send me the instructions so that I can set it up. Please do not allow anymore orders to be placed on my account without some form of conformation from me.
If an employee doesn't help you here, contact one of their Billing reps at the phone number on your bill or 1-800-Comcast, chat with them using one of the "Account and Bill" options at https://support.xfinity.com/chat, or visit a Service Center if one is nearby (check locations and hours at http://www.xfinity.com/support/service-center-locations/) and have them reverse the charge.
In addition to getting the billing corrected, consider setting up a Purchase Pin on each of your cable boxes/DVRs to prevent this from happening. See https://www.xfinity.com/support/articles/how-to-block-purchase-of-pay-per-view and/or https://www.xfinity.com/support/articles/x1-parental-controls-turn-puchase-protection-on-off.