The perplexing part is that I was never informed about the ban when my ex closed the initial account. Had I known, I would have refrained from further deposits. Seeking advice on potential resolutions and exploring oversight from a gambling authority for crypto casinos seems prudent, given the circumstances. It appears unjust to be notified of the account ban only upon attempting to withdraw, especially after multiple deposits and losses.
For this fact alone, I think you have a good case, why should a casino allow a player register, deposit and play and loss, then deposit again, multiple times without issues, but upon winning and requesting a withdrawal, the casino then remembers the player has a connection with a banned account, this is total fraud and one we all should not accept but fight against, allowing such attitude to thrive in the gambling ecosystem won't be good for its growth.
This is a clear case of scam, and what I did suggest you do now is, go to the scam accusation board and create a scam accusation against Rollbit, remember to first read the rules, and follow the laid out procedure, which includes you providing as much evidence and proof to your case, as possible, I believe that if Rollbit wants to maintain their reputation, they would allow you withdraw your money in one peace, else, they might lose a lot of customers.