Hello there, someone seems to have got scammed by your usual "KYC" trick after winning a huge amount. Not that it's very unusual to see something like that happening with your site but your inputs on his accusation will be appreciated here https://bitcointalk.org/index.php?topic=5203845.msg53156014#msg53156014
Unfortunately, that's a common thing for almost all new and even old reputable bookies. Big win = Locking account and refusing winning payout.