As evidenced on the screenshot I provided above, Rollbit does use a geoblocking system.
The evidence in the screenshot is not sufficient, as the event might have occurred after KYC (we do not know; let the OP clarify). This is precisely the essence of my argument.As for the other points, about profit from past sessions, I believe what Rollbit mean was that they will confiscate the rest of the fund on OP's account. Suppose OP is at a loss, they will return the deposit amount, but since OP is in overall profit, the remaining balance will not be available for OP.
You might believe that, but I have no reason to take the casino's side (especially based on a hypothetical belief), particularly considering the timing of the ban. Rollbit cannot arbitrarily choose when to ask for KYC (although we know that it will always happen after a big cash-out request 
).