I've reach and escalate it to my contact to be retried with above proposal, their answer is that it's final, the decision can not be changed for a reason I can completely understand. However, I also escalate to my other contact to ponder over it. They're from a different division of the one who I previously in touch with, so the division probably have a better wiggle room.

This staff is rather hard to be reached, so you might want to have some patience. Though I have to say that I sincerely think the chance is close to a minimal.

As previously stated, casinos usually respect a division's call and try to not to overturn the decision made by other division in order to not abusing their power.