rizone = fake memory - sorry to say but it not 16GB, it may report that but its not, just search "ITCHEE" or "RIZONE" and you will see many cases like yours im afraid - and no, it really is NOT 16GB
use the tool and have a look at this site
H2testw 1.4 – Gold Standard In Detecting USB Counterfeit Drives SOSFakeFlash
and if ebay - complain and get refunded