@bp54 I personally think that you should have realised by now, after all the responses you've gotten from various people, that your case simply CANNOT BE RESOLVED via a normal Mediator!
The proofs you have shown are convincing, but it's your evidences against the casino's - what you really need are evidences from OFFICIAL RELEVANT BODIES, such as ADRs or even Lawyers, evidences collected by the right Bodies to support and fight for your case!
Needless to say, this move may incur costs and fees to you, but that seems the ONLY WAY to resolve your case.