Oh. Great question, it can be confusing sometimes. If you have the Kaz-F019 model, it won't work. You need download:
You need to install the Qualcomm Drivers and QPST, then open QFIL (just search qfil from start), plug in your phone, and flash the KAZ-F119 Firmware. You can probably find instructions by searching google for "How to flash new firmware with QFIL". However, if you are having issues, or it's too confusing, I'm happy to help out more.
Note: Doing this will delete all your phones data!
(If you have the KAZ-F119 model, you should be fine already. You can check by going to Settings > About Phone)