I have the same thinking there's no existing scam accusation against Duelbits prior to your issue but I'm sure that they are fully aware of this issue.
I'm not trying to defend OP here, but as the old saying goes: there's always the first time. The fact that there were no accusations prior to this one doesn't change anything.
Do you remember Terra Luna? It wasn't scamming people until it did scam all of them.
A week is a lot of time, to be honest. The longer it takes the worse it will look for the casino, even if eventually they'll return his money. Actually, from a PR point of vies, at this point it woud've been better if they could prove that OP was at fault. At least that would explain why it took so much time (evidence gathering).