I need delete my credit balance from Apple ID

See -> Check your Apple ID balance

Check your Apple ID balance – Apple Support (UK)

scroll to ⤵️

If you have Apple ID balance you can't use

You can't redeem or return Apple Gift Cards, App Store & iTunes Gift Cards or unused Apple ID balance for cash, except as required by law. If your jurisdiction allows the refund of redeemed gift balances, you can contact Apple Support to request a refund. When you contact Apple, include the following information:

• Your Apple ID.
• The refund amount.
• Your current delivery address.

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