This just adds to the belief that you really don't know anything, and that your lack of knowledge has been the main contributing factor to this snake's decline. Do you think IBD is the only snake disease that there is? IBD is the only reason that quarantine is an absolute must? Things you say are just coming across as extremely nonsensical.
You say that you only gave it a "few drops" of water, but you're then trying to say that that is what made it urinate less than a minute later? You truly believe that a few drops of liquid will trigger a urination, and that it takes less than a minute for that water to pass through the snake's digestive system? I cringe just reading half of what you're saying, I have to doubt that you're able to type it with a straight face. I really get the impression that you know next to nothing, and you're just making it up as you go.
If the vet. report shows a preexisting illness, I think you're owed a refund. If not- TOS be damned- I don't know that I could hold it against the guy if he told you go pound sand. You have no credibility, and frankly, I really don't believe much of anything you're saying. I can't trust that you'd admit to something having happened to the snake while in your care.
To those who are saying that the seller should issue a refund no matter what, let's take it to an admittedly ridiculous extreme. If the health guarantee is binding for 30 days, regardless of the buyer's actions, he could cut it up and deep fry it for snake-poppers, and still be owed a refund. As long as he did it within the 30 day period. Point being, I simply don't believe that a realistic interpretation of the circumstances should be completely removed from this equation.