Subscriptions on Google Play renew automatically. If you wish to unsubscribe to a certain app/promo, you can cancel it on Google Play.
1. Access the Google Play store and tap on the Menu Make sure you are logged-in in the correct Google account where you set up your subscription.
2. In the Subscriptions tab, you'll find the subscriptions you currently have and will be able to cancel any of them, as you wish. Just tap Cancel subscription and follow the onscreen instructions.
We hope this helps!