This exact same thing happened to me only mine lasted 6 days. I was completely devastated. Mine was also from petsmart and was told that he was in good health, the first 2 days seemed normal. The last 4 were terrible and very sad.
We just raised one since August and he has just died Feeling sad and not sure about why but something to do with the lighting i thinkI appreciate the kind words. It has been a bit discouraging but we will definitely look into those podcasts and find another sweet chameleon to give a great life to. Thanks so much