OP, allow me to ask again because my question here was not answered, what's the scam here? Did they stole, voiding your bets, lock you away from your account, or deny you a winning for no legit reason?

Your case is you're feeling underappreciated for your wager and you thought you're being misled by an up to 50% bonus. The nature of that bonus and the wordings has been explained numerous times. May I suggest you, again, to simply leave rollbit, look for other gambling site and lock this thread? Because unless any of the questions on the paragraph above is a yes, there's no case here, they did nothing wrong thus far.