As per my experience, I have no bad experience depositing, playing, and withdrawing with Duelbits. I also been there since 2020, but I'm a smaller gambler compared to you OP.
Goodluck
I am an active participant of the Duelbits campaign and still am and all my friends, I referred here can vouch that they don't have any issues with withdrawing their earnings I'm 100% sure that it will be resolved fairly, if OP deserves his earnings he'll get it, the last scam accusation was easily resolved and end well, now that it is posted here they will find ways to resolve this, I'd like their support and you can vouch that they are transparent, OP update us for any development.