Any contract where one of the parties knowingly signed without "good faith" is null and void on its face.  If it can be proven that CoinMarket was grossly negligent in handling of user goods, or perhaps actively intent on stealing them, then the terms and conditions license will not protect them.

However, they can just say "We were hacked!  The coins are gone!" when, in fact, they "accidentally" left the back door open and one of their friends came in and swiped the goods.  In this case, you'd need the force of law to prove anything, and they're probably too busy investigating evil things in Norway like labor law violations and illegal health care providers.  You're basically going to the police and saying "Hey!  These guys stole my Sword of Power and then their Orc's slayed my kingdom!  Arrest them!"  Yeah, that'll fly.

But maybe they will listen...