To cancel your subscription is fairly simple. depending on the place you purchased the subscription from, follow the following instructions:
Just login in to your account from the website, then go to edit my profile, from there in the top left corner you will find the details of your subscription, and the link to cancel subscription (picture shown below). Once initiated, an email will be sent to confirm the cancelation, you need to click on the confirmation link to cancel the subscription (if the link is not clicked the subscription will not be canceled).
Just click on the user picture in the App's main page in the app where you created the account. Then click on change subscription in the side menu that will be shown (as displayed in the picture shown below). If you're subscribed you will be taken to the subscriptions page in your account (Google Play or AppStore). From there you can cancel the subscription like any other subscription obtained through these stores.
