Please note: The cancellation will come into effect in the next month (or year), because the subscription for the current month (or year) has already be in force and cannot be cancelled.
We developers are not able to help check use's subscription and cancel it; it is all under Google's control. If you failed to cancel it, please contact Google Play support team for further assistance: https://support.google.com/googleplay/answer/1267137
If you've purchased an auto-renewing subscription of premium account, it will be listed under the Manage App Subscriptions section of your Apple ID---Account Settings.
To cancel the subscription, you may refer to: http://support.apple.com/en-us/HT202039Please note the subscription is automatically renewed within 24 hours by the end of the period unless you choose to cancel the subscription.
We developers are not able to help check user's subscription and cancel it; it is all under Apple's control.