Re: Is asking me again and again to login
Wondering if you are signed in (to your device) with your Apple ID:
How to: Sign in with your Apple ID - Apple Support
See if you can edit the details after you are signed in.
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Else, If that is not the solution:
You may want to try online to edit your payment methods in your account:
Here's the link to Apple ID log-in:
https://appleid.apple.com
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or
If your credit / debit card details have changed:
You may need to add the new payment method, before you can delete the old one.
How to add an Apple ID payment method:
Add a payment method to your Apple ID - Apple Support
How to delete an Apple ID payment method:
Remove a payment method from your Apple ID - Apple Support
All the best :-)