Hey, firstly, welcome to the forum and sorry about the experience. From other forum member's perspective, it's very hard to draw a conclusion from this case on who is right and who is wrong as most casinos don't share the information about their fundings

What I want to know is that during the KYC process, were you asked to prove your source of funds?

Secondly, have you tried other alternatives of resolving the issue, such as askgamblers or casinoguru? It's much easier over there, since the mediators get to see the proof that made the casino believe that you were money laundering and decide if the judgment was far or not.