I had the same blowout with them, same scenario 2 years ago. I spoke to Michael the nat sales manager. He listened pretty well and ended up getting my commission to me.
On the one hand they are great in the sense that they get deals done quick, best pricing around and not a lot of bull****ting around. When they pay, they pay on time. On the other hand, I can not understand why they continue to do this, where they are stiffing people on commission. It really does them no good.

As for small claims, do not even bother. You will never collect.
Call MIke the nat sales manager, you might have wanted to do that prior to posting this.

Good luck and sorry that happened to you.

Good luck