Can you post your bet history so that we can have an idea whether you can gain any edge through multi-accounting (I am not saying you did)?
In my humble opinion, if there is no possibility of gaining any edge or circumventing betting limits, then the original poster must be paid in full, and after that, it is up to the casino in question to allow him to play further or not.
There’s no need for that. The casino already claimed that the OP has other accounts and even asked them to provide a list, implying there’s more than one, since it’s called a list. Also, I don’t think Rollbit would reveal the accounts or IPs used, as that would likely violate privacy laws, and they could face penalties for doing so. That’s why having a mediator is crucial in this kind of situation.