I experienced almost the same problem when I sent ETH to ETH address on yobit.net

And I noticed that the wallet on yobit doesn't show any indications that there's an upcoming ETH that came from my outside wallet address but later on it was done successfully.

6 days of wait is very long and it's an unusual delay, have you ever try contacting yobit support? (Oh well their support sucks).

The problem is that you didn't provide any txid for us to see if you did successfully sent it to their ETC wallet address.