I think they think you are not the real owner of your account because you no longer access with your 2FA authenticator.
If you have the secret code, you can recover your 2FA to another software like Google Authenticator; it does not ask for fees and it's free and once you recover your 2FA regenerate a new secret code from Kraken, and make sure you write down your secret key offline.
If you didn't save your secret, then your last option, as suggested above, is to contact support.
Try contacting them on X here
https://x.com/krakenfxAnd what does that mean? He's not the first person to lose access to his 2FA and certainly won't be the last. I'm not sure if it was an online wallet, exchange, or both, but I've had also lost access to my 2FA device, broken device and didn't save any of the security codes, and I had to go through the verification process again and wait one or two full days till I was able to deactivate the 2FA, by sending a notification on my email.
That way, if I was a scammer, the original owner would see the email and undo the process.