The said subscription will appear as an "Google Play subscription" on the account settings page of the dartfish.tv account.
Note that for those subscriptions deleting the dartfish.tv account will not cancel the subscription on Google side.
To cancel a subscription please follow the steps described on the Google website : Manage Subscription.
If you did not cancel the subscription before the end of the Trial or renewal, you need to contact Google to request a refund:
How to request a refund on Google