How to remove icloud storage subscription and remove my card.

I am looking to Stop my icould storage Subscription on my Ipad air 2 and I am not able to remove the card or stop the subscription. When I check the subscriptions options I do not see anything when i try to delete the card details I see there is an active subscription on this account and require at least one payment on file. How to stop the Icloud storage subscription and remove the card.