^ maybe they were trying to open the phone using hands and not proper tools.
I remember the service centre guys kept flashing the original firmware over and over whenever I visited them to get the my Nokia 6303C fixed. I didn't knew it was a hardware problem and they took me for granted.
When I got to know what the actual problem was, it was too late. The phone was out of warranty.
The service centre refused to replace the damaged Power IC on the phone because they weren't authorised by Nokia India to do repair work. I was like "WTF, then what are you people doing here?"
They said they'll need to send it to Delhi for repair work and shipping will cost 4k alone while the phone was for 7.5k.
(b*tch please I can travel to Delhi and back on train well within 4k)