Posting on the ANN Thread of Gamdom is the best thing to do, and if OP really confident about this claim then the site needs also to explain this here in the forum. Though, of course we can't trust this claim easily since there's a trust issue with OP and we don't know if this is just another thread to ruin the reputation of Gamdom. Again, if you are going to post an accusation about the site, its always better to provide all your proof so we can also help you with this claim.
If you browse the OP history, The only thing you can see on most of his post is about Gamdom, He created already a scam accusation thread, brought up this topic on official Gamdom ANN thread and also this thread which is an extra scam accusation thread in gambling section. Probably OP already do utmost effort on bringing up his case to the public. The only problem was Gamdom representative is long inactive here in the forum. They only answer concerns via live support and email. It will be very hard to get an answer here in forum from them.
If you will also check more on OP's history, you will be able to check other scam accusation that has the same format from this one on different gambling platforms as well. OP's isn't really doing his utmost effort on most of his accusation as he only provide limited proof and screenshot that really doesn't support his claim. For example on this case, He only provided a conversation from Telegram from which it doesn't provide legitimacy if that's the "CEO" or not. He's only provoking us by saying that he will provide more proofs such as video evidence which I doubt he'll even show it.