Just this past Saturday I bought a perennial hibiscus plant in a 1-gal (I think) pot. It was a nice color and its heart shaped leaves looked very healthy. It's pretty tall. It's Tuesday now, I haven't had a chance to put it in the ground yet. And it looks awful. The bottom leaves are wrinkly and wilty looking and some of the leaves toward the tops, while still shaped properly, have a blackish discoloration on the bottom parts, toward the point of the "heart"

Can anyone help? What have I done wrong and what should I do next?