If you could have approached it like an adult you probably would have gotten the resolution you were seeking.
Am I reading this right? You're saying it's OK for DaDice to steal leen's coins because s/he didn't act like an adult?
I would disagree.
Taking no sides here.
But one point is leen93 would have kept quiet if she had made a profit.

And, I am sure leen was aware that 20 BTC was the limit. He might have even invested at 30x kelly if it was available.
From my experience, if you really want an issue to be fixed however bad it is (since I don't think this issue can be fixed retrospectively), you should first talk properly with the admin and staff associated with it.
I can't see the invest option, so can someone say exactly how much risk is say 0.5x kelly subject to?