Petland Sick puppy with kennel cough died 6 days after purchasing Hoffman Estates Illinois

Check on the Illiniose Animal Welfare Act. If you believe and have proof they have broken any of the statutes, you can contact the bureau of animal health and welfare, make sure you know which statutes. I don't live in Illiniose, so please check on this yourself. Someone else on here may be able to help a little more.

I am sorry for your pain. I have to ask, was the major contributing issue to the pups death hypoglycemia (or does it appear that way)? Is that why they are refusing to cover it? There are very few circumstances in which that would be covered by anyone.
Any time someone intends to hold someone else responsible for a death a necropsy with any appropriate additional testing showing a definitive cause of death (and therefore responsibility) is imperative. If the cause of death was hypoglycemia, but the necropsy showed a liver shunt that might change things. There would then be a causing factor for the hypoglycemia other than the usual contributors.
Again, I'm sorry for your loss. *just my opinions*