Charlotte, you say the box was only 3" high rather than 6" high? I must respectfully disagree. Not to get nitpicky here or anything, and the ONLY reason I'm responding to this is because yes Ray is a person I've known a while and done quite a bit of business with with no problems, but that cigarette lighter you have standing next to the box is over 3" tall itself. According to my ruler, standard lighters are about 3.1" by themselves. Up against your box, it seems like it has another few inches to go. Yes they make some taller and some shorter, but these are obviously shorter. And looking at the lighter in comparison to the dead snake, it's obvious the lighter is AT LEAST 3" tall.
Lastly, the "tiniest of boxes" thing. Think, honestly think, about what snakes live in in the wild. They generally don't go for the most open room. Snakes are people, or even mammals, and it has been proven that smaller is often better, especially in stressful situations, such as shipping. While your snake might not have been packed properly in the box, the box size should have been just fine, and the bag size was certainly fine. Sorry your snake didn't make it, and I hope you get your money back, though I'm sure you will if you'll just have a bit of patience.