I suppose the casino has nothing to do with slot machines games' results, since they come from a third party provider, who is responsible for the RTP percentage announced and every mechanics involving the game. The only thing gamblers have in their favour is the word and reputation of the company which develops slots games. Since it's not enough and since the gambling community is so united nowadays, thanks to the internet forums and social medias' groups, it shouldn't be hard to spot a bad or cheater slots' provider and gather proofs to move an organized petition to casinos asking them to remove the brand from the betting platforms.