Sorry to hear that, I know you did what you could trying to fix it. Did anyone give you any idea what was causing the problem?
I've found out that lots of people don't take very good care of their ball pythons. After they have them for a while they try to sell them. You can find BPs on craigslist pretty cheap and you may even save them from dying. Both that I've bought from the original owners have been very under weight.