Use askgambler to open a dispute against Mavericks if you are very eager to this case.
Judging by what holydarkness said, AskGamblers doesn't mediate in disputes that concern MaverickGames. He couldn't find the casino on their website. I also did a quick search and couldn't find it either. CasinoGuru could be of assistance, though, if the player wanted their help. Based on OP's results, I don't think he want's to take this any further.
Even if he does, there's nothing CG can do. Based on OP's statement I quoted below this post, OP reached to their licensor, Isle of Man, and the licensor agreed on the findings made by the casino and ruled the case in favor to the casino. CG can not intermediate this as they will not intervening disputes that's already ruled out by the "highest possible" authority.
IIRC, every licensor stated that they're the last step of solving disputes due to this very reason, that their decision is final, and that gamblers should have been sure they've exhausted any possible means of resolution prior to escalating it to them
This is what also happened to the "neighboring" case of
kamen1, where CG will not intermediating a case that's already ruled out by the licensor [the verdict of the said case is quoted below the line].
I wrote to both the support service and the licensing authority. Nobody protects the interests of the player. I took my deposit a long time ago, because I understand that no one will return my winnings. I just want to warn new players that this casino is a scam.
Dear kamen,
As you have confirmed that the regulator decided in favour of the casino, and as we do respect such decisions, I'm afraid there is nothing more that can be achieved here. I only recommend you collect your deposits back and let us know afterwards, so we can close this case accordingly.
I am sorry I could not be of more help on this occasion.
Best regards,
Tomas