Re: "I’m trying to add another MASTERCARD to pay for my I-Cloud storage and
unable to remove my old card which has been canceled"
Your Apple ID is the one account you use to access Apple services like the App Store, Apple Music, iCloud, iMessage, FaceTime, and more. It includes the email address and password you use to sign in as well as the contact, payment, and security details you use across Apple services.
You may want to check which payment methods Apple can accept in your country or region:
Payment methods that you can use with your Apple ID - Apple Support
As you have an active subscription, you will need to add a new card, before you can delete an old card.
How to add an Apple ID payment method:
Add a payment method to your Apple ID - Apple Support
and
How to delete an Apple ID payment method:
Remove a payment method from your Apple ID - Apple Support