This is often how these devices display their 'death'. If nothing else, you might schmooze some OfficeMax or BestBuy clerk to let you insert that card into a Mac and see if there's any change in 'recognition' behavior. If not, then I'd say "dead" and get another one.
There is free software that can often let me recover files that are accidentally deleted or even reformatted devices. A Quick-Format only re-writes the Formatting Header location, and renames the data into a "now it's deletable/overwrite-able" state. These 'recovery' packages can sometimes be used to read a newly-formatted device therefore and recover prior data.
Not always, but sometimes. When a Format is my last resort, I choose "Quick Format" and then use something like Piriform's freebie RECUVA, which I've installed on my computer.