Why would people refuse to accept a refurbished product that is throughly remanufactured and individually tested for free, and instead they would only want their original device. Even after it is crudely repaired.
As for the camera problem. Maybe the lens unit is stuck. It's a hardware problem. Restoring obviously will not help. you should try shaking and slapping your phone, hoping to free the stuck lens. If you can't make it to work, go to Apple and have it replaced. Or you can replace the faulty camera yourself.
Also if you're following the ifixit guide to replace the camera. DO NOT REMOVE THE BATTERY. You do not have to remove the battery to get to the camera. The battery has to be discarded after removal for safety reasons. Do not try to disassemble the camera unit or manually freeing the lens. it is very easy to wreck the camera or get dust into it. You'll get very noticeable dark spots on the pictures