There is a ROM flashing tutorial on this forum using SP flash tool.
You can get ROMs for your device from:
1. http://bbs.ejiayu.com (Chinese official forum for Jiayu)
2. http://www.needrom.com
3. LeWa ROM for your device may be available at Phones section of this forum.
Good luck!
Thanks!!! 
have the same problem 
thanks!
where can I find the official rom for my phone?
you can watch discavery channel ;P
GREAT FORUM!! found help for my w100s 
iPhone 5s
yes but its worth it.. 
unless you want the 5s
absoulutly YES! 
Can anyone recommend me a good forum in india…??
thanks..
does anyone know if the w100s support hebrew??? 