Dear member of SanDisk Community, welcome.
Please friend, do not grieve more, return it, is dead, ist kaputt…
Write protection errors occur when a flash drive detects a potential fault within itself. The drive will go into write-protected mode to prevent data loss.
There is no method to fix this.
To verify the issue is related to the UFD and not your computer, we recommend that you try plugging the UFD into another port on your computer.
You should also try the drive on another computer if possible.
You might have a pleasant surprise, if can contact with SanDisk Technical Support who will replace the device if it’s authentic and is within warranty. Link: http://www.sandisk.com/about-sandisk/contact-us/
To obtain the internal data of the UFD, you can use (apps portable, free): - USB Flash ChipGenius, http://filecloud.io/rqa7etmv
- USB Flash DriveLetter, http://filecloud.io/vgqzcdyh
- USB Flash Deview, http://filecloud.io/srp2hegw
To find out more on this, see here: http://forums.sandisk.com/t5/All-SanDisk-USB-Flash-Drives/HELP-how-do-i-reomove-write-protected-message-from-my-16gb-flash/m-p/323924#M8925
Regards, Alfred. (Google translated)