An answer to my question

Concern moved here to the Billing help section for greater exposure to Comcast corporate employees (The Digital Care Team) for assistance. 

Hey @user_w1fs42, Thank you for visiting our official Xfinity Forums Community support page. We greatly appreciate you taking the time to share your experience regarding the Xfinity account and billing. I would be more than happy to offer my assistance looking into this further for you.

I would highly recommend visiting our 'View your Xfinity billing statement history' support page where you can view the past months billing statements. From here you can quickly compare your last billing statements together. The service bills could be changing due to one-time charges, rate changes, promotional roll-offs and more. You will be able to compare the changes and view any notifications of price changes and promotional roll-offs on or after page 3 of the billing statement. 

Please let me know if you have any specific questions when viewing the billing statement and do not hesitate to post a screenshot for review with any personal information removed.