It's hard to find such sites because the money a review website earns are from their affiliates. So they will not tell anything that will go against their money machine. I saw another user suggested the scam accusation board. But it's always hard to find the sites if you are going only from the board. I can suggest a way to find it from the search engine easily.

Consider the casino name is: bitcoingirl casino

On the Google, search with the following term:

Replace bitcoingirl from the search key with the casino name. You will be able to see any topic that was posted for the casino and their status.