Quite tough to tell who is actually in the wrong here. Firstly, GekkeBelg has provided a ton of proof to prove his case, but he has faced similar issues in multiple crypto gambling sites based on my research.
Secondly, as @panjul07 mentioned, Denis didn't really provide any evidence to prove his statements against GekkeBelg. Complicated!
And have you also checked out how those cases ended?
First of all, I have had zero problems in 95% of the sportsbooks I have used in the past, but indeed I have had 5 scam accusations on Bitcointalk in 5 years. 4 out of those 5 have admitted they were wrong and paid me out in full. 1 out of the 5 has not paid me despite Askgamblers ruling in favour of me. This was Coinplay.com. Needless to say that their reputation is destroyed, they struggle to get any more new customers and their topic on Bitcointalk is totally dead. That is what happens if you steal fair winnings and don't make it right.
However, on the contrary, other websites such as Wintomato, Buff, Owl and especially BC.game who stole from me, are now back into a good reputation on here and since they paid me I leave them completely alone. The ones who see their mistakes and correct it, are free to have a bright future on Bitcointalk.
It's totally up to Coins.game to decide which road they want to go: realize their mistake, correct the situation and pay me out, and the scam accusation will be closed and they can continue to build a trusted user base on here. Or, keep their stolen money and be known for being a scam betting site (with a red flag above their topic).