Hey there, I’m sorry you’ve been having such a difficult time trying to get the email on the account updated.
Since you no longer have access to the Yahoo email linked to the EA Account, the next step would be to go through the account recovery process with EA Help. Your linked Xbox Gamertag can be useful information when trying to verify the account, along with things such as the original email address, your EA ID, and any EA purchase or invoice information you may still have.
You can find the account recovery steps here:
https://help.ea.com/en/articles/ea-account/locked-out-of-ea-account/
Unfortunately, we aren’t able to verify account ownership or change account details through the forums, so EA Help would need to handle the recovery and determine whether the account can be verified.
If you contact them again, I’d recommend providing as much of the account information listed in the article as you can.