I agree with Dragon Tail and others who suggest the media.
I work in the print industry and it is the way to go.
TT and ACA always ask to email in info for stories, but they need an angle. The same for newspapers.
A few sick and poorly kept reptiles will probably not be enough to get them interested.
Whoever contacts the media, from the state where the shop is, needs to give them something they can 'beat-up.'
Tell them these poor sick, disgustingly kept reptiles are in such a bad state that young children, who might receive or buy them as pets, could be in danger of catching some disease or virus.
Or, because of the atrocious conditions, where these reptiles are kept, could they be carrying viruses or parasites that could infest a family home?
Are people at risk of contracting disease, virus or parasites etc just by entering the shop?
I'm sure a phone call to a journo, detailing possible outcomes similar to these examples could spark some action, especially from a reporter with a local paper.
It's obvious the shop has parasites, but they are behind the counter.
Good luck with it.