Again, mention in passing that you're considering a BOI. You can still post said BOI when all is said and done, but if he absolutely refuses to work with you, that'll be one more thing you can add. It's already bad business to not only not send the snake you asked for, but send a snake that wasn't even shown in any of the photos. It could have just been a mistake, but when sending a snake that wasn't listed in the first place, you know there's something fishy going on. Especially if it was a low-quality that you received that he didn't imagine would go anywhere else.