Michael,
I feel your pain. I just lost out on a Clickbank commission.
Similar situation, a friend purchased a product from my site and told me to look out for a credit which never arrived.
I emailed support and never heard back.
When I read their FAQ's, it stated: "The affiliate (if any) we associate with any sale is determined by an automated tracking system. Any decision made by this system is final and not subject to petition or debate."
When I read further, I think this is what must've happened:
10. Can I send customers directly to the URL that ends in "/?hop=nickname"?
No. The "?hop=..." is just information we pass along to the publisher's web site AFTER recording a legitimate referral via hop.clickbank.net. If you bypass hop.clickbank.net there is no way for us to track your referral.
Hang in there.