I have no idea why people keep telling you that the provider makes all decisions. Maybe they don't know or are just trying to shift blame. Each sportsbook makes the final decision and if someone get sued, the sportsbook will be the defendant, not the provider. What if two sportsbooks use the same provider but have different rules. The odds provider does exactly what the name says, they are odds providers with the addition of being a profiler.
Because it's four different contacts from four different casinos telling me this? Wait, five. Two doesn't even have the issue with this whole provider matter, and I ask under capacity of due diligence and "hi, sorry for being nosy, if I may pick up your brain for a little for a case with neighboring casino...", they don't have issue with this provider-thingy, so they shouldn't, whatsoever, have a reason to assign blame? They all came to the same answer. Should that be enough or should I mull over the possibility that they somehow communicate with each other behing our back and conspire to mislead us and shift blame? I can ask to two more casinos contacts, just to be sure.... three.
If I were you I’d go by what they tell you but they are wrong and common sense should tell you that.
Actually, looking at my contact and my list, I can ask to at least five more casios. Should I? I'll do it if it's needed and deemed necessary. And what if their answers are all the same? Ten different casinos contacts, across different providers, tell me one same thing, and common sense should tell me that they are all wrong?
Though what I believe as a more important question to ask here is: what should I put as the final verdict of OP's case? Resolved because Rollbit gave their explanation? Unresolved because Rollbit refuse to refund him? I personally lean toward unresolved, but conflicted as I am quite sure their ToS covered the matter of confiscating entire fund. And as always, I am here not to pass judgment, rather [mostly] to walk with the players to the end of the case.
So, overseers, inputs are welcome. [And I am serious with asking five more casino reps just to clarify that matters of provider-make-rules to rest]