River Belle Casino - Winnings annulled as per 'management decision' with no further details given

10.05.2018 in River Belle Casino I won $ 709. At their request I sent all the requested documents. I was not paid winnings. All the winnings were annulled. It's impossible to log in into my account - the account is blocked. On my e-mail inquiries, why did this happen, the casino representatives told - this decision has been taken by Casino Management and there will not be provided any additional information regarding this from the casino side.
I'm sure they have to provide all the information.