Yes, those stats are very odd.
What I'm looking at is:
8,257.55 (rake)
-2,201.32 (paid bonus)
____________________
6,056.23 (rake minus bonuses)
x 30% (the amount their site claims they pay affiliates)
= 1816.67 (this should be your share if my numbers are correct)
Unless, I'm not doing this right... but I think that I am
Good Luck, those stats seem to me like they owe you money.