We are in the same boat.
I've been a member at freebitco.in for 7 or 8 years now and my stats show that I have played more than 20,000 Free Rolls (excluding WoF spins).
So far, I have never won the $200 nor the $20 prize, even though I should have statistically gotten them about 5 times in total by now. If my math is correct, the probability for rolling one of the three highest numbers at least once in 20,000 attempts should be 1-(9,997,5/10,000)^20,000 = 99.33%. On the other hand, I vividly remember rolling all of the three lowest numbers at least once.
Furthermore, even my results for the $2 prize seem a bit off. I think I got it like 3, 4 or 5 times, tbh I didn't keep track, but it's definitely lower than the expected 8 times.
Maybe I am also just extremely unlucky, but the longer I keep playing, the more I am doubting the self-proclaimed fairness of the site and that all numbers have equal odds.