It seems MegaDice have been active with the gaming licence issuer and will fight their corner. Rather you spend money and instruct a lawyer maybe you should contact the gaming licence authorities in Curacao and liaise with them until they actually make a decision about whether MegaDice should ensure you get your 19+ BTC or not. After all, if they decide in your favour then you would have saved all that money and hassle with the lawyer and investigation.

No doubt you will proceed as you see best but I gave my advice on the subject.