How to unsubscribe: 

  1. On the Home screen of your phone, tap the Settings app
  2. Tap iTunes & App Store
  3. Tap on your Apple ID/email address 
  4. Tap View Apple ID. You might need to sign in.
  5. Under Subscriptions, tap Manage.
    If you don't see a subscription in iTunes and are still being charged, make sure that you're signed in with the correct Apple ID.
  6. Use the options to manage your subscription. You can choose a different subscription period, or turn off Automatic Renewal.
    Turn off Automatic Renewal to cancel a subscription. Your subscription will stop at the end of the current billing cycle.

For more information and screenshots view the Apple support page:

Why are you unsubscribing?