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.