My phone suddenly closed and now its on a bootloop

My phone stopped working suddenly.

It closed all of a sudden and now its stuck on a boot loop with the messege 'your system has been destroyed, press powere button to shutdown' .

I tried factory reset it didnt work. I gave it to a service shop and he couldnt fix it either.

He said the NAND flash memory could have been hit and bc its hardware it cant be fixed.

Is there anyway i can fix it?

I also tried to unlock the bootloader but it said 'getService Token failed' or smth.