I agree that if this guy kept these kites he is totally lame.
But, I think Greg is right here.
Proving he received the kites might prove difficult on this one. This could come back to bite you in the butt if this guy is a real lamebo and actually decides to step it up a notch and sue (if that is indeed a possibility).
I would figure out the specifics before you go much further.
A lamebo is a lamebo. Only mess with them if you know you can win. They will use any trick or out to do the wrong thing and unfortunately, this makes it hard to force them to do the right thing.