Jb, I'm sorry to hear about your experiences. You should try writing a detailed email to CJ support - though don't hold your breath for a prompt response or any resolution. In my experience the merchants always manage to wriggle out of paying commission.
It is quite typical for merchants on both CJ and other networks to not track commission back to affiliates. In the experience of me and my friends it is anything between 15 and 25%. It's a staggering figure, but we can't do anything about it - apart from pulling out of this glorious world of affiliate frauding, sorry marketing, which I am doing.