There is no EASY button, or fix for account management.
If you have a new mobile number, then that is why you are not getting the reset code, as the service is sending them to someone else, who is getting them, and changing the account info as we speak.
this is why you should always create accounts from a landline network (PC of laptop), recover the account a couple of times, then once you are familiar with that process, you attach the mobile number to the account. Now, regardless of the mobile number, you can access the recovery options, and not relying on the pesky (lost, stolen, or bill not paid) lost mobile number!
I understand this is too little, too late!