Try formatting the drive, sometimes you'll get the original size. Ten years back there were many mp3 players with fake 1gb storage, which when formatted would show only 256mb.
They're very common overseas. When I lived in Shanghai, the markets would have tons of these. Unfortunately, they aren't always ludicrously oversized/underpriced. I had some data I lost on a 16GB drive that was only 4GB(IIRC). Granted, that was years ago
You can see them on Amazon if you look for flash drives. A few manufacturers will have really large drives (256GB or more) for ridiculously low prices, along with a 1-star rating and a lot of people claiming they are fakes.
There are plenty of legit companies selling devices that are legitimately those sizes, but you will pay a lot for them.
Of course, since flash media prices seem to drop by 25% or more every year, it won't be long before there are real devices at the prices of those fake ones mentioned above.
"Error prone" would be accurate. Put some videos on it in logical increments (1GB, 2GB, 4GB, 8GB, etc). Find out how much it takes before earlier data starts being overwritten, and you'll know how large the drive actually is.
