How do I get a refund for an unexpected 11-dollar charge from Apple?

• What did you determine when looking in your Purchase History?

View your purchase history for the App Store and other Apple media services - Apple Support

• Did you view or cancel any subscriptions here?

View or cancel app subscriptions on iPhone - Apple Support

Apple is not just randomly taking money out of your account. If you signed up for a free trial and did not cancel at least 24 hours before the trial period ended, then you have the subscription that was authorized when you double clicked the side button with the free trail end date and subscription price showing on the screen. Without knowing how those charges occurred, your financial or account information may be compromised and you have to take further action.

In most cases, all transactions in the App Store are final. At times, Apple may provide a compassionate refund, but it should never be expected.

Request a refund for apps or content that you bought from Apple - Apple Support

If you don't have the charge showing in your purchase history or a subscription from the links provided then it is not an in-app purchase that is managed by Apple and you can only request a refund when you see the charge in your Purchase History.

You may want to provide a screenshot of what you see at both of those locations along with where you are seeing the charge. Just make sure it does not contains and personal/financial information.