If you had walked away after winning, you wouldn't have felt the game was rigged. I don't think slots are rigged because you experienced a losing streak, you were simply unlucky. Other gamblers have played the same game and made a good profit.  Anyway, if I observe that this incident happens consistently in a casino, I might try another casino just to check if the former one is fair. Buy if you are playing on a reputable casino, just know it's luck..