I'm on the same page. I'm guessing the distributor is pretty shady. From what he told me I don't understand why they would be dying. If his temps are accurate, 87 hot side, and I'm guessing 75-80 cool side, there's no reason they should have died in such a short time unless there was an underlying issue.
I didn't think about cleaners though. Wouldn't most of the other animals be dying though? He has a bunch of other snake species, rodents, frogs, etc.