HitBTC have blocked the user's funds (about 160,000 USD) and do not want to return them, although the client has already provided them all requested documents:
Maybe this is the same person - https://old.reddit.com/r/Bitcoin/comments/e9z11e/hitbtc_do_not_respond_to_tickets_frozen_a_huge/?sort=confidence
but there's an interesting post here suggesting something I hadn't heard of before - https://old.reddit.com/r/Bitcoin/comments/e9z11e/hitbtc_do_not_respond_to_tickets_frozen_a_huge/fan86o4/
Verifying with some sort of parent company and then Hitbtc responding. Dunno if it works or not.