Useless

1. Open the Settings app.
2. Tap your name.
3. Tap Subscriptions.
4. Tap the subscription.
5. Tap Cancel Subscription. You might need to scroll down to find the Cancel Subscription button. If there is no Cancel button, the subscription is already canceled.

See the following Apple articles:

If you want to cancel a subscription from Apple

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

If the subscription that you want to cancel is not listed

If the subscription that you want to cancel is not listed - Apple Support

See also ->  Downgrade or cancel your iCloud+ plan

Downgrade or cancel your iCloud+ plan - Apple Support (PH)

Contact iTunes Support for assistance. See the Apple Support articles below for contact information.   

iTunes Support – world wide   -

Apple Support schedule phone call     -

Billings and Subscriptions   -

Apple on Twitter