I think he's aready proven that he doesn't care. He has the money and you have a snake, so he thinks his job is done. Doesn't seem to care that you don't have the snake you want. As a breeder he should now what it is to go after a certain look with your snakes, and yet he dodges your questions. Doesn't say why the one you ordered died, doesn't offer another snake with the look you are going for, he just gets snippy. It's a shame because I looked him up on the BOI and he seems to have a pretty good rep. I guess you just never know. I would say, though, if you do wish to take it to the BOI, you should probably do the refund. If you keep the snake, people are just going to be like, "Well you kept the snake, so what's your problem?" Especially if he has a fan club built up on there.
That said, if you have concerns about the welfare of the snake, then keep it and sell it to someone you trust. It's a really crap situation all around. Does this guy have a website? He's definitely added to my Do Not Buy From list and I have a bookmark folder full of such people that I'd like to add him to.