To be honest and laid it out in the open, that's what I tried to pursue when I said "considering another means of resolution," to allow you to retain your deposit with some terms. However, they are firm on their decision and they're very sure with their findings. Best options you have right now is either escalate it to their licensor or to just drop the case, as currently there is not any other visible resolution possible.

As for licensing, you can rest assured that they're licensed. Like acroman08 said, you can check this by clicking the seal of validation on their website. It's a mandatory element of a licensed casino under Curacao Licensing to provide this means of verification on their website. Image as below. If you click them, you'll be redirected to GC's page as shown on the image next to it, verifying Rollbit as their sub-licensor.



While for holding your winnings and deposit, though there are times in the past that platforms go lenient by allowing the other side to withdraw their balance and agreed to part ways, I think Rollbit has the right to seize your winnings and deposit upon breach, it's one of the clause on their Terms of Service that you agreed,


If you're not satisfied with this, please follow my advise to raise it to their licensor, Gaming-Curacao. We are not sure what'll happen there, but you'll have another shot there rather than here as your means of resolution on this case kinda met its... dead end here.


Looks aesthetic or not, that platform is one of the only four master license holder for gambling ever issued by Curacao Gambling Authority. And though Antillephone is basically the most... exquisite --or so I heard-- there will be no more master license issued again, so they're as legal as it can get.