I've seen this time and time again.
It breaks your heart, it really does. I've shed a few tears over situations like this before.
But I cannot stress the importance of saying something to whoever is in charge at the time.
Drag them over and point out the snake. My favorite line is, " Aren't you ashamed of your store for letting this poor animal get in this condition ? It's obviously in very bad shape, you can see it is way too thin, it has retained shed all over it's body, I doubt it can even see. This set up is obviously not what this snake needs to stay healthy. I shop here frequently, and I have to say I am appalled you'd let things get this bad. It reflects very poorly on you and your store. I trust you will see this matter gets taken care of promptly?"
No, it isn't what I'm really thinking, but you really do catch more flies with honey. If you give the manager a way out, they'll usually take it. It has worked for me a few times, and a few times it hasn't, but at least I tried.
Gale