I tried to send my ETH from poloneix to my yobit ETC adress by mistake.  I asked both yobit admin with the nickname dominikherzog and support desk.

he replied as "Yobit generates a separate Ethereum and Ethereum Classic deposit addresses because of security requirements." without creating a solution.
 But on etherscan website I check my ETC wallet. On my ETC wallet there are 19 ETH is shown.
 So the transaction is valid therefore there should be a privatekey.  I can refund ETHs with ETC private key of yobit. It is not shown at pending deposit section on yobit. I asked them to send me the private key. 
they refuse to send it. And could not understand why?. I  am the owner of the wallet adress. There is a valid transaction but not shown.
I am following my ETHs on  etherscan. If I detect a transfer out of my control , I dont know what to do ? I hope they wont steal my ETHS.

dominikherzog previously help CryptoManiacHen onthe below link, he does'nt want to help me.

https://bitcointalk.org/index.php?topic=1902605.0

Keep away from yobit. They don't response , even if I was mocked by admins on chat section.