Here's an Apple Support link to help you in managing your subscriptions:
See or cancel your subscriptions
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.