download sp flashable stock kitkat rom (it also works when u hardbricked ur device)

most important thing take a backup of ur rom if u dont know how to take a backup see here

stock kitkat 

download rom here

download sp flash tool here

step1 extract rom

step2 open sp flashtool and select scatter file

step3 select firmware upgrade option

step4 click on download and connect ur phone to usb cable{ur phone must be switch off and usb driver must be installed in ur pc} 

or see the screenshots