If you want to unlink the auto-debit payment with Apple ID, please confirm that you have cancelled all your subscriptions first.
You can unlink Apple ID through your iPhone/iOS device settings:
Open 【Settings】 > 【User Name】 > 【Payment and Delivery】 > 【Click the payment method that needs to be unlinked】> 【Remove the payment method】.
If you have any other issue during this process, please contact Apple Support: https://getsupport.apple.com/.