Keep contacting them everywhere you can and don't give up easily. $10k might be enough to try legal action if you can figure out which jurisdiction is applicable. Kraken could at least state how much they want to charge to recover the funds and do it once in a quarter to a batch of users.
It's a risky job for them. To recover this amount they have few hundred thousands dollar worth of coins will be at stake. Depending on their setting it could be very complicated because I am sure in their cold wallet not one person is holding the keys. But again for a person, $10k is a very good amount of money. And considering this, I hope Kraken will take the risk and help the user to recover his fund.
Most do but recovering wrongly sent funds must be something hard for them to do. But try talking your luck with the support though your chances are very low. I don't remember a case where someone successful recovered their money.
I too do not remember any such cases to be resolved but again I have never seen such amount too. So best of luck.
How is it a risky job for them? There are no other funds on my ETH address other than PaxGold worth of 10K$... It is not like a collective ETH address with millions of funds from other users on it. You only need to deposit enough ETH for gas and a private key. Should only take a few minutes. I understand because of complex audits and security measures it may take a while to arrange. But once it is all set, accessing my funds does not put other users' funds in danger.