How do I fix the ‘Billing issue’ problem?

That bit about making multiple Apple IDs just sounds to me like it would make the situation worse. Do you mean you made multiple accounts? I'm guessing you have something on there that is from an old account that has some residual issue with it.

This could take a long time resolving online so you may wish to contact Apple where somebody can real-time help you with this issue.

Contact Apple. Click here --> https://support.apple.com/choose-country-region Select your country, then a product. If you don't see one that handles your issue then keep experimenting with selections until you reach one that gets you a chat session or a telephone call and get the representative to redirect you.

or:

Contact Apple for support and service --> "See a list of Apple phone numbers around the world."

Click here --> https://support.apple.com/HT201232

Apple says: "Some purchases might require that you have a credit card on file, even if you use your Apple ID balance to make the purchase." - from: What you can buy with your Apple ID balance --> https://support.apple.com/HT211187

For a variety of reasons Apple will almost always require a functional payment method such as a credit or debit card be present when downloading anything from the iTunes or App Stores that isn't totally free (so, for example, a "free trial" that turns into a paid subscription isn't ' free'), even if the item will be paid for with Apple Account balance. The only solution to satisfy this requirement is to add a valid payment method*.

This document explains how to 'Change, add, [review,] or remove Apple ID payment methods' on a Mac or Apple mobile devices; click here --> https://support.apple.com/HT201266

Change your Apple ID payment method if you don't have an Apple device --> https://support.apple.com/HT210755 - PC, MS Surface, Android, Chromebook, online at tv.apple.com

'If you can't remove your last payment method or use no payment method with your Apple ID' click here --> https://support.apple.com/HT203905

- When updating an old card and have ongoing subscriptions, or are the organizer of a Family Sharing group, you may need to first add the new card and make it the primary payment method before deleting the old card.

- A payment method is required if you're using your account with the App Store for the first time.

If you still have problems, click here --> https://support.apple.com/choose-country-region/media-services Select your country, then a product. If you don't see one that handles your issue then keep experimenting with selections until you reach one that gets you a chat session or a telephone call and get the representative to redirect you.

or:

Contact Apple for support and service --> "See a list of Apple phone numbers around the world." - https://support.apple.com/HT201232

Additional resources:

*'Payment methods that you can use with your Apple ID' --> https://support.apple.com/HT202631