Confirm you have canceled any subscription automatic renewal (if you simply delete an app this does not cancel subscriptions):
Review the information in this support article by clicking on the link to learn how to cancel a subscription from Apple. ➔ If you want to cancel a subscription from Apple - Apple Support
If you subscribed to this directly with a third party, see: About purchases not billed through the App Store or Apple In-App Purchase - Apple Support instead. You need to work directly with the vendor, not Apple.
Notes:
• "If you signed up [which involves very intentional steps by you or a user of your device, accompanied by warnings along the way] for a free or discounted trial subscription and you don't want to renew it, cancel it at least 24 hours before the trial ends." Note that by using an app like this you are automatically agreeing (always read the fine print) to this happening, are responsible for reading if this will happen, and canceling the subscription before the trial ends. E.g., Bait and switch on Apple apps - Apple Community
• Deleting an app does not cancel a subscription.
• An existing subscription will normally continue until the end of its term and may then renew automatically. Stopping automatic renewal is effectively canceling it. "If you don’t see Cancel Subscription, then the subscription is already canceled and won't renew." The "Expires" date means the current subscription will just run until then. Note special conditions for some countries: About canceling subscriptions in Germany, Israel, South Africa, or Türkiye - Apple Support
• Read the article to see what to do about subscriptions that do not appear in your list. If you still can't find a subscription, contact Apple Support using the link at the end of the support article.
• Canceling a subscription does not automatically start a refund.
• If you had a free trial previously, you do not get a second one and a subscription will start immediately.
• This thread (particularly posts by MacJimID) outlines complex scenarios regarding subscriptions and trials. ➔ Refund request for unintended Snapchat Pl… - Apple Community
If you wish to pursue a refund, follow the directions in this support article about how to request a refund for apps or content that you bought from Apple ➔ Request a refund for apps or content that you bought from Apple - Apple Support According to Apple’s terms, refunds are only made to remedy defective or unavailable product. You can request a refund on other grounds but those refunds are entirely discretionary and not guaranteed. Special terms also apply for some countries: About canceling subscriptions in Germany, Israel, South Africa, or Türkiye - Apple Support
Read this support article for information about how long it takes to receive a refund (if one is granted), and how to check the status of a refund for apps or content that you bought from Apple --> Check the status of a refund for apps or content that you bought from Apple - Apple Support
Apple’s position appears to be that people need to be proactive about purchases, canceling subscriptions at least 24 hours before trials end, and ensuring that others are not able to make unsanctioned purchases on a user’s account. Note that if you allow—intentionally or not—another person access to purchasing on a device, or through Family Sharing if you are the Organizer, you are taking responsibility for things they do. Apple offers these features to help you avoid this situation:
On your device you can use Screen Time to prevent unintentional or unauthorized purchases from the App Store, in-app, and other Apple services. —> Use Screen Time to turn off in-app purchases on your iPhone or iPad - Apple Support
Also on your device, require a password for App Store and iTunes purchases —> Require a password for purchases in the App Store and other Apple services - Apple Support
Use Screen Time as part of parental controls on your child's iPhone, iPad, and iPod touch —> Use parental controls to manage your child's iPhone or iPad - Apple Support
If a child made this purchase on their device as part of Family Sharing, consider activating Ask To Buy—> Approve what kids buy with Ask to Buy - Apple Support
Use Guided Access to permit a person to only use a single app —>
Lock iPhone to one app with Guided Access - Apple Support