There is no scam here that I see based on the evidence provided in the screenshots.
OP deposited and withdrawn without placing a bet so it got blocked. The support allowed him to withdraw provided that he promises not to do it again, or bets the money. I guess he chose to bet the money and lost it, then he started this defamatory thread.
I think your guess is close to reality because have been playing in Duelbits for years now and i even participated in their campaign as in my own experience the support is constantly answering problems and this is why i doubt what OP is claiming here, the support wont just block him with 544 dollars in claim .
Next time make sure there's enough evidence to support your claim because posting a conversation where they tell you that they blocked the withdrawal but will allow it to go through but only this one time proves nothing. They played fair if you ask me, you did not.
and this also open some thinking about how and why he was blocked because it is clearly show that the team responding to his Issue from the beginning .