The reason I say this is biased is that the sequence of random numbers internal to the random number generator has repeating patterns. After reaching the end the numbers repeat again in the exact same order. Second, there is repetition in smaller cycles in terms of even and odds numbers. Therefore when performing millions or billions of trials I avoid taking the modulo of the raw random number but prefer regular division. Because of the larger repeating cycle I generally limit my simulations to two billion random numbers.
All combinations are equally likely to win.
If it does win you will have to share the jackpot with the hundreds of other people who also chose the same simple set of numbers. See my blackjack appendix 4 . They must be cheating. I do not deny that there is cheating going on. However just because you had a bad session does not nearly rise to the level of evidence required to make a convincing case against the casino.