Do you have solid evidence to say that the keno game in Stake is rigged or it is just because you experience more losses than wins there?
For alternative in house keno games, there are some casinos you can try such as Jacksclub, Bitvest (different keno game), bc.game, betfury, coins.game (new casino), shuffle (new casino).
However, if your accussation against stake is based on your lost only, I think alternatives will be just alternatives and you may accuse them all rigged if you lose your money.