How can I cancel gamepass subscription when I’ve been locked out my account?

Customer support can't help verify your identity or recover your account, this is to protect customer privacy. If you can't provide the info needed for the online form, then there's sadly nothing else that can be done.

Okay Kyle I appreciate you’re quick responses. I understand , thanks for your help I’ll keep trying.

No problem David. Please reach back if you have further questions, take care.

Sorry one last thing that will gnaw at me. I can prove who I am. I have a valid drivers license, passport and proof of address. If I could just talk to anyone at Microsoft or xbox support I can easily prove who I am, they have my bank details. If they could just send the code to my new number and not my old one I could also verify easily.

I'm afraid there's nothing further that can be done if you can't verify your ownership of the account through the online form. To protect customer privacy, Microsoft can only help customers verify their account ownership through the online password recovery process.

If you remember any new details that might help with the recovery process, it's encouraged to keep trying to recover your account using the online account recovery form.

https://support.xbox.com/help/account-profile/manage-account/lost-password-solution