Go to iPhone Settings > iTunes & App Store.
Tap your Apple ID at the top of the screen.
Tap View Apple ID. You might need to sign in or use Touch ID.
Tap the subscription that you want to manage.If you don't see a subscription but are still being charged, make sure that you're signed in with the correct Apple ID. If so, you might have subscribed directly with the provider and not through iTunes. In this case, contact the content publisher or app developer directly to cancel your subscription.
Use the options to manage your subscription. You can choose a different subscription offering, or tap Cancel Subscription to cancel your subscription. If you cancel, your subscription will stop at the end of the current billing cycle.