Hello,
Apple Pay is a payment conduit used for purchases in physical stores and websites and is free, it does not charge you direclty either.
Purchases done through Apple pay will show up on your payment method's statement identifying whatever they were for directly.
If the charge is showing up as "apple.com/bill", then that has absolutely nothing to do with Apple Pay.
If you get a recurring charge for 11.99 labeled as "apple.com/bill" it suggests you started a subscription for an Apple service or 3rd party app.
That can usually happen if you download an App with a free trial and never cancel it.
You can log in to https://reportaproblem.apple.com to find and identify the charge.
click here ➜ Get help with charges from apple.com/bill - Apple Support
If it is a recurring subscription, you can cancel it on an Apple device, Windows PC, Android Phone or online by following the steps in the link below.
click here ➜ Cancel a subscription from Apple - Apple Support