We hate to see you go, but since you subscribed via Roku, cancelling is something you'll need to take care of on your end directly on the Roku platform.
You can cancel your subscription by following the steps in this article.
If you run into any trouble, please reach out to Roku Support so they can assist you further.
Note: We are unable to cancel this Roku subscription for you. You will need to do it from your device manually.