Please, zero out my credit balance.

You're not communicating with Apple when you post in the Community. We're all just fellow users, helping out as we have time and knowledge to share. None of us here has any access to your account to do anything with it. Either enter in a credit or debit card temporarily and buy something more expensive than your remaining balance, or contact iTunes Support and ask them to clear your balance for you.

iTunes - Official Apple Support

Regards.