Q: Apple i store shows i have a balance but won't allow me to purchase a song.

Hello kingdave10,

Thank you for using Apple Support Communities. 

I see that you wish to redeem the balance in our iTunes Store account. But this a take it you wish to receive a cash refund of the balance. The support article: See your iTunes credit balance, addresses this question. 

You can't redeem or return iTunes Gift Cards, Gift Certificates, and unused store credit balances for cash except as required by law. If your jurisdiction allows for refund of redeemed gift balances, you can request a refund by contacting iTunes Store Support, selecting a support category and topic, and including the following information in your request detail:

• Your Apple ID.
• The store credit refund amount.
• Your current shipping address.

Additional information might be requested for verification purposes.

Best regards.