Why do I need a payment method installed when I’m not charging anything?

If you are being asked to enter a payment method, Apple has multiple criteria* requiring the presence of a payment method, even for free items. Since you may be encountering one of those situations, you have no option but to enter a valid payment method if you wish to continue downloading. Read the support article Add a payment method to your Apple ID - Apple Support about how to do that. The payment method may not be charged if you also have account balance or the item is free, but the payment method has to be present. This next article lists valid payment methods for different countries but note that in this situation Apple Account balance alone apparently may not meet the requirement and you need to use another payment method until you find one that satisfies Apple's requirement (often a credit or debit card): Payment methods that you can use with your Apple ID - Apple Support .

If you have already entered a payment method, use the first link above to check it. If a message appears in red there is a problem with it. If the information is still correct and current, contact your financial institution.

* Ref.:

Add a payment method to your Apple ID - Apple Support

"To make purchases from the App Store and use subscriptions like iCloud+ and Apple Music, you need at least one payment method on file."

If you can’t download or update apps on your iPhone or iPad - Apple Support

- "You might need to have a payment method on file, even if the app that you want to download is free."

Remove a payment method from your Apple ID - Apple Support

- If you have any active subscriptions, you must have at least one payment method on file other than Apple ID credit.

- You might not be able to remove a payment method if you have a balance due.

Sign in with your Apple ID - Apple Support

- "When you sign in to the App Store and other media services for the first time, you might need to add a credit card or other payment information."

How apps, content, and subscriptions from Apple are billed - Apple Support

- You can’t charge gifts to your Apple ID balance. If you send a gift or gift card, your primary payment method is charged.

- Some subscriptions might not be charged to your Apple ID balance.

What you can buy with your Apple Gift Card or Apple Account balance - Apple Support

"Some purchases might require that you have a credit card on file, even if you use your Apple Account balance to make the purchase."

It charging anything?

You will get charge when you purchase stuff from the App Store / iTunes Sore.

You can download free apps, but you may need to have a valid payment method on file, even if the app you want to download is free. 

Free apps has also In-app pruchase.

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I had me cc added prior and my 7 year old accidentally charged about 850.00!

To avoid the case in the future, see ⤵️

If other people have access to your iPhone or other Apple device, change the device passcode and never share it with others.

Change your Passcode -> Use a passcode with your iPhone, iPad, or iPod touch - Apple Support

Change your Apple ID password -> Change your Apple ID password - Apple Support

• Create a strong password for your Apple ID, It is best if your password consists of eight or more characters and include upper and lowercase letters, and at least one number. You can also add extra characters and punctuation marks to make your password even stronger. 
• Never provide your password, passcode, security questions, verification codes, recovery key or any other account security details to anyone else. Apple will never ask you for this information.

Then see this Apple article: What to do after you change your Apple ID or password

What to do after you change your Apple ID or password - Apple Support

Require a password for App Store and iTunes purchases

Require a password for App Store and iTunes purchases - Apple Support

Manage App Store purchases, subscriptions, settings, and restrictions on iPhone

Manage App Store purchases, subscriptions, settings, and restrictions on iPhone – Apple Support (UK)

Prevent in-app purchases from the App Store

Prevent in-app purchases from the App Store – Apple Support (UK)

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and Apple apple didn’t respond to my refund requested.

If you have requested a refund, you must wait until Apple has approved. Then you will receive a message from Apple.

Refunds are not guaranteed. For more information, see the Terms & Conditions.

If Apple has notified you that it is not eligible for refund, we can't help you, sorry, we are also users of Apple products & services like you. 

Some purchases are final.

If you still need help, get support from Apple directly -> Get Support or call Apple in your region see -> Contact Apple for support and service or check -> here for more support and assistance.