I used kraken a lot in 2017,, but never logged in again.
Never had any problems with them.

And all cryptocurrency exchanges have terrible customer support.. you are probably talking to a bot.

Your history is odd. Why didn't this guy withdrawal the funds instead of doing those crazy  trades?

Did you check where the illegal login came from? You can check tbhat in your account, or ask them for login history. Could it be a family member or something like that?
It's sad, but nobody should ever leave funds on exchanges, unless if you are actually trading a lot.