wow, I'm seeing some amazing assumptions here.. saying maybe didn't meet any wager requirements and etc.. trust me there isn't anything like this at all. deposit. and wd =)
Well good to know that it isn't the case.
I visited their TOS and found this confusing

You are only allowed to withdraw BTC instead of ETH and it has nothing to do with confirmation at all if we follow that.
It could also be a case of failure to update their terms.
He stated above that he do deposit in ETH too after his BTC transaction is still pending out of boredom. So definitely he can withdraw in ETH once his BTC pending transaction is confirmed.
The only problem was OP didn't stated how long he is waiting for his transaction to confirm. The mem pool is sucks right now and I understand what OP feels about his pending transaction. But it's not necessary to accuse a casino for a scam when they are just waiting your other balance to confirmed. This is my first time to see this kind of issue.
In sportsbet I do deposit ETH and BTC currency at the same time with same scenario with OP. Sportsbet allow my ETH withdrawal even though my BTC is not yet confirmed.
Another thing is that we did not know on which bitcoin address the coins were send ? If we know then we could check on blockchain for details like how much fee was applied and also if we know the transaction hash, we can accelerate the tx too with the free services avaiable on the forum.