Remove funds from apple id balance

Buy something more expensive and pay the balance with a credit card or contact iTunes Support and ask them to zero balance your account. See the Apple Support articles below for contact information.   

iTunes Support – world wide   -

Apple Support schedule phone call     -

Billings and Subscriptions   -

Apple on Twitter

Messages chat with Apple

You either spend them in the iTunes Store, Apple Store or Books Store or if you have less store credit than the cost of a single item, contact Apple Support and they can remove it for you.