SanDisk Cruzer Blade 16GB write protected error

[wtfson]

I have a cruzer pop 16GB for three weeks and i had used it only once i have saved some and some movies and after i access it the second time it’s already “write protected” which i can access the file within the usb but i can’t delete and add files and i can’t even format my usb i have used many kind of usb and i have never encountered this kind of error. my OS is windows vista i had already tried it to different computer but it always the same error. i have done all the remedies posted in the net but still nothing and i have read a thread that sandisk already know this defects in their usb and my question is why is it still being sold in the market and they even said that sandisk said there are still no remedy and just “replace” the usb wtf. how can a company sell ■■■■ and just get away with people money? I was really interested buying it because i saw it was very cheap compared to my earlier sony usb that is still working i should have trusted a brand that i know i can depend on