this one stumps me too....whats your weather like just now over there? could it have gotten a chill on the way home from the shop? your care in a week or so wouldn't do this to the plant...unless you sat it in a glass of water, then it would be all mushy...but the roots look good....very odd....I think I would return this plant and get another, when they start out funky, it will be an uphill battle keeping it alive....good luck!