You may want to try to get hold of these folks. I think from doing a fast google that they are familar with this species and perhaps could offer you some advice. Worth a try at least.

http://www.sunshineserpents.com

Sadly you've learned rule #1 of snakekeeping....don't trust the majority of pet stores.

I hope you are able to get help for this snake or at least, for the sake of the other snake, find out what is going on here.