If your story is true, then it's really uncalled for, And I agree with you that it is really unprofessional of rollbit to act in such manner, from the kind of reputation they've built in the gambling community, one would assume they should be way above such petty things as trying to scam users off their winnings, but then, let's not conclude yet and allow them to respond to the matter, might probably be a glitch in their system or something similar, what ever be the reason, I hope it's resolved amicably without any party feeling cheated on.
Well, we have heard so many similar cases against this casino and all have to do with the interpretation of their terms and conditions not sure if it is because Rollbits have complicated terms of service or the players are simply misinterpreting it.
But for the sake of clarity, the team should have made a public explanation as to some complicated and misinterpreted terms in their service to avoid all these constant accusations.