Why did my zebra finch die 4 days after you got it?

If it was from a pet store, bring it in to them, with a reciept. It could have been that it was old, not fed properly, cought a virus, dehydration, or maybe even trauma. Did it seem fine when you got it? My advice, contact the seller and explain the situation. Sorry about your loss. I have a zebra, named Molly. She lives with 3 button quails and now she thinks shes one. Get another finch, though. You got everything for it, why not! If your new to them, they are a great joy to have. And again, sorry about your loss.