Sorry to hear of your catastrophic experience with Windows 10, Steve. I hate getting into those hours-long tech support phone calls...people who can't speak English very well, won't pull their headset microphone around in front of their mouth, mumble, etc. The second and third time I ask them to repeat an instruction, I would think they could clean up their act; some just won't do it.
I hope most people's experience converting to Windows 10 is like mine. It was pretty smooth. Of course, I'm not using any W10 features I don't fully understand, stayed with Firefox, Thunderbird, Open Office, AVG. It's funny how well those free things work.
Best wishes on getting it straightened out. I think you should sue but, of course, that would cost a lot more than a new desktop.