i cant remember where exactly i encounter that site first, but they appear in a lot of sportsbook sites, also on oddsportal. i deposit 200€ and won around 500€, then i got limited after one bet and tried to withdraw. they took the whole money, including the amount i deposit.
For let's say we will disregard their reputation and credibility, do they told you why it turned out like that? Something like you violates the terms or something along those lines. We don't know the whole story.
But yes, you need to move on as probably even with exchange emails, they won't allow you to withdraw even your deposits. That was an unprofessional act.
This proves that even a licensed site will do a shady service.