Microsoft 365 features that help users manage their subscriptions, account settings, and billing information.
I understand that you're trying to remove an expired credit card from your Microsoft account, even though you've already added a new payment method. To better understand the issue, could you please clarify the following? What happens when you try to remove the expired card? Is the Remove option unavailable, or do you receive an error message? Do you currently have any active Microsoft subscriptions, such as Microsoft 365, OneDrive, or Xbox Game Pass?
In the meantime, I suggest visiting https://account.microsoft.com/services to check whether the expired card is still associated with an active subscription. If it is, try changing the subscription's payment method to your new card before removing the old one.
Please let me know what you find so I can guide you further.