Mac with Ultra USB3.0 16G B

I have tried everything I know to do which is obvious to me that is lacking considerably…

None of the JPEGs I put on the thumb drive has ever been recognized as readable. I erase them and try again, same thing.

I went through utilities, erased the drive and it still shows that 7.74 GB of the drive is used. There is only one partition, it shows nothing but says only a little over 8gb of the 16gb memory is available…

From day one this has never worked even though i followed all the directions that came with it.

ARGH!!!

How do I start from scratch with this thumb drive??