The universal written contract we have states that the casino agrees to pay your winnings which sportsbet.io fails at miserably.
Quote it.
https://bitcointalk.org/index.php?topic=4509006.
"Sportsbet.io prides itself on its secure and trustworthy betting service[1], with withdrawal times of around 1.5 minutes[2]- amongst the fastest in the industry!"
[1] How can a casino be trustworthy if they don't pay their player's winnings?
[2] OP's winnings didn't arrive in ~1.5 minutes. How long it has been now?