There are many methods to get recovered from write protected error from pen drives. To format a transcend write protected pen drive use the following utilities one by one and find yourself one that works for your pen drive.
1. Transcend AutoformatThis tool from transcend allows you to format USB drives or memory card that cant be formatted with using the normal format feature of windows. It can reformat and recover format error data on your usb drive.
2. MformatThis is another utility that can be used to format erroneous pen drives. It can format/partition the disk space. After formating, unplug the device and reconnect. You may need to repeat 2-3 times to get results.
3. JetFlash Online Recovery
This tool is developed for Transcend JetFlash USB flash drives. If your pen drive has to be repaired, just connect and run this program so that it'll be connected to their servers. You can format the usb disk by clicking "erase data and format drive" when prompted.