I’m assuming that you’ve followed the story and do not want to work with them any more?
If so then :
It’s pretty simple really. Tell your players the truth.
Tell them about players who have not been paid.
Tell them about contracts not honoured.
Tell them that with this additional news you cannot recommend this place any longer as a SAFE place to play. Remove the links.
1) That will stop new players from joining.
2) That will warn existing players.
If people still continue to there – then THAT is their own fully informed decision.
But underline the fact that you (or anyone else) will be unable to help them recover funds if the casino decides not to pay out – as it HAS be proven to have done in the past.