It seems like that you need to give more effort to push the team. You can try to join in the official telegram group of hitbtc and then try to ask the admin directly to escalate your ticket

https://t.me/EN_HitBTC

There are lots of people who have been doing the same thing as you. I shall remind you that you must never use a lot of money when you are wanna dealing with this kind of exchange site.
Im still using hitbtc but i was using this one only for short term trade.

Just try to take a direct conversation with HITBTC admin on telegram group. I hope your problem will be solved as soon as possible.