Sorry to hear of this Chillybean. I wonder if the nursery had stressed the plant because I think Eastern Redbuds are usually easy to grow. I take it you watered it for the first moth or so?
They tend to grow quickly to blooming size, but are short lived trees. I had a nice old one in my yard that I had to cut down as the winter snow cracked it in half one year. Because they self sow, though I have several offspring, one of blooming size already. Maybe you would have better luck of you bought a younger one?