I learned Poomse Korryo through a DVD, showed him, and received my Cho Dan.
Kukkiwon uses the term il dan, not chodan for 1st Dan. But if you are suing him for your 1st Dan, why does your profile state samdan (3rd Dan) as your rank?
Personally, I would never sue any of my instructors, no matter what I thought they did to me.