On this page, you will find the official link to download Xtreamer Q Stock Firmware ROM (flash file) from GoogleDrive. Firmware comes in a zip package, which contains Flash File, Flash Tool, Driver and How-to Manual.
How to Flash
Step 1: Download the stock firmware on your computer.
Step 2: Rename it to update.zip.
Step 3: Place it in the Phone SD memory.
Step 4: Flash it through the recovery.
[*] Take a Backup of your personal data before flashing or installing the firmware on your smartphone. As this helps you to recover the personal data whenever any thing wrong happens.