Cruzer Blade USB 2.0 16GB - restore 14.5GB full capacity

my SDCZ50C-016G (Cruzer Blade USB 2.0 16GB) after various formatting (& various installing USB bootable OS), total capacity decreased from 14.5GB to 14.3GB

besides DISKPART & other Windows built-in tools i’ve tried also third party tools/software (such as GParted Live, sfdisk on linux, etc)

with sfdisk on linux i was able re-make a stock empty primary partition FAT32 LBA (0xC) with standard MBR (MSDOS on GParted) & starting at 32 sector to full capacity, but total capacity still remain always at 14.3GB (instead 14.5GB)

$ sudo sfdisk /dev/sdX

>>> 32,,0xc
>>> write

how can fix this?!?
how can restore full original capacity (14.5GB)?!?