You have no liability in disclosing who it was that screwed you over.....maybe you can help somebody else avoid these pr*cks down the road.....if he is any kind of businessman he would make it right and avoid the court of public opinion.....
The problem you have in court or with the credit card company is that you paid it along the way without drawing the line at the repair stage.......you were in a tough spot and sometimes in life you just get stuck with what I call the "dummy tax"....I've been hit with it many times before myself! I try to live and learn but I would make that guy pay by exposing his businesses practices...
I'm telling you as a lawyer if you are telling the truth and stating the facts you won't have any problems.....I wish I was there in Iowa, I'd love to file suit for you, pro bono, just to stick it up his a**