mine did that too! and I thought it was dead! that was last summer but this spring when I was going to dig it up and replace it I noticed some green! it is coming back with really nice big leaves. I hope you will not have to wait as long as I did. you might try some vitamin b-1 but with no leaves you won't want to use too much water. if the leaves look diseased in any way I would get it off your property and return it!
Bless you! Susie