Question: Q: Got a receipt for an item that I didn’t purchase

More than likely it is a spam message. A phishing attempt for you to provide account information. See this, Recognize and avoid phishing messages, phony support calls, and other scams - Apple Support

You can check your Purchase History to make sure it isn't there, See your purchase history for the App Store or iTunes Store - Apple Support otherwise just delete the message.

In order to get a refund, you need to open your purchase history so you can submit a refund request to Apple. 

Please follow the steps below: 

1. Click this link: https://reportaproblem.apple.com 

2. Sign in to your Apple ID that you use to purchase the subscription. 

3. On the Report a Problem website, under the Purchases tab, click Report a Problem to the subscription of the app you want refunded. 

4. Choose a reason for the problem, describe your issue, then tap or click Submit. 

Based on the information that you provide, Apple might provide a refund directly, refer you to the developer, require additional information, or might deny the refund request based on refund eligibility.