I've just been told by my Nokia Care Centre that because I've flashed my eMMC on third party software,my warranty is void. He said it should have been done by a Nokia 'Agent' using their software.

I wasn't aware that this was the case. I told them that my device had issues before the flash(random reboots,memory issues etc.) and it was almost definitely the hardware. But he told me that was highly unlikely and that "that's the problem with using 3rd party software" and it's probably the flasher program which caused the issues.

Is he right? Am I shafted?

Cheers