To stop an App Store to keep charging on my app

There is only one way to cancel a subscription. You must cancel a free trial 24 hours before the trial period ends. If you don't it automatically becomes a paid subscription.

Managing auto-renewing subscriptions -

If you want to cancel a subscription from Apple - Apple Support

If you had your bank stop payment or refund a charge, Apple has likely disabled your account. You will need to speak to Apple Support to clear up the issue.

Worldwide Apple Support -

Contact Apple for support and service - Apple Support

M1 Mac mini, macOS 14.2;  Watch, series 7 GPS/cellular, watchOS 10.2; iPad Pro 2nd Gen, iPadOS 16.7.3; iPhone 12 Pro, iOS 17.2; TV 4th Gen, tvOS 17.2; HomePods, audioOS 17.2 and Airport Express w/ Airplay 2

This support article explains how to cancel a subscription from Apple on an Apple mobile device, Mac, PC, and online ➔ If you want to cancel a subscription from Apple - Apple Support , or this video will only tell you how to do it on an iPhone ➔ https://www.youtube.com/watch/XXx-J-ueCtE

Notes:

• You might need to scroll down to find the Cancel Subscription button.

• If you don’t see Cancel Subscription, then the subscription is already canceled and won't renew. An "Expires" date (instead of "Renews") means the current subscription will just run until then. "Resubscribe" is just in case you change your mind about having it end.

• Deleting an app does not cancel a subscription.

• If you don’t cancel trials more than 24 hours before your renewal date, your subscription might renew.

• If you don't have an Apple device, see the options near the bottom of the support document.

• Many subscriptions are set to renew automatically until you intentionally cancel them.

If you can’t find the subscription that you want to cancel, use this shortcut to jump to the section about what to do. --> If you want to cancel a subscription from Apple - Apple Support If you still can't find a subscription, contact Apple Support using this issue-specific link at the end of the section. --> https://getsupport.apple.com/?caller=kbase&PGF=PGF63006&category_id=SC0060&symptom_id=23208

If you still have problems, contact Apple online using this page ➔ Choose your country or region - Official Apple Support Select your country, then a product. Alternatively, see a list of Apple phone numbers around the world ➔ Contact Apple for support and service - Apple Support