HitBTC seems to be holding my 11 ETC hostage

[Rippology201]

I opened an account with HitBTC in November anticipating public trading of an ico ended TIO coin, which never occurred.  After a week or two realized I'd better move on or trade there but found the site would always crash or stall out. This went on until January when I decided it was pointless to continue trying the same routine week after week and tried to Withdraw my 11 Ethereum coins ... to no avail.  When I paste in my Send To Address a little pop up says:  "This does not look like an Ethereum Address" even though it is my Wallet, which I know to be in working order; then the Authentication Code that I add correctly tells me the numbers are wrong, and this keeps going back and forth from the Address to the Authentication Code like a short-circuited robot.

Emails thus far have fallen on deaf ears except the first time I sent an email and they answered some time that week when I was not at the computer - gave me one hour time limit to answer them.  Anyway, if anyone has similar experience would like to hear of it, and how to solve this dilemma.  Thanks, ciao.