As Serpens pointed out, there are others who have posted here who are waiting for their money. I just looked at your case. The 400€ were deducted from our bank account on 1/5, so Kraken isn't holding your money. It's either held up at our bank, or somewhere on the way to your bank (i.e. at an intermediary bank). If it's held up at our bank, then there's just no excuse for the delay, especially since you've said that you'd just like to have the funds credited back to your account. If it's held up somewhere else, then this is a situation that can take a long time to resolve in some cases. I think the support staff helping you with this has been assuming the funds are already sent from Fidor, but it's not clear to me that this is the case (their feedback has been rather vague), so this will be clarified with Fidor right away.

I see that you've had many successful withdrawals through another bank account. I'm not sure why the withdrawal with this account has been a problem, but we're certainly going to look into it. Are you certain this bank accepts SEPA? Our experience has been that there are a few EU/EFTA banks out there that don't. That's probably not the issue, but worth asking about.