Z10 screen freeze

While using my suddenly it gets hanged, the screen starts to faid to black, and switches off. I have to pull the battery to restart, but during restart it fades and fails, goes off. After 5,6 battery pulls, the thing starts. There is a video in the YouTube showing that problem

I have given it to the service center, they resolved the problem, have done the fullll security wipe and reloaded the software. It was fresh then. They told there is no problem with the PCB. It was a software issue.

It's been a month after that.
Now the problem has again started. It's becoming worse.
Is there any solution!

Z10 001 IN