To delete a subscription renewal of an app with automatic payment, Settings-iTunes Store and App Store- touches that says Apple ID (in Blue with your id) ... in the window that appears touch View Apple ID, you'll to ask for the password of your ID, you appear Subscriptions (management or administration) you go in there, play the subscription you want to cancel and disable the automatic renewal.
with the billing issue. Settings-iTunes Store and App Store- touches that says Apple ID (in Blue with your id) ... in the window that appears touch View Apple ID, you will ask for your ID password, billing information and complete missing data you there to solve the problem, I hope you serve greetings.