Sorry to hear that, Terry. It's a shame to lose you after only 8 posts.
It sounds like you've been very unlucky, which does happen, and I appreciate how frustrating it must be. I've had pretty bad luck with Tamron lenses, but I still like them and continue to shoot with them.
I don't think the issues you've experienced have anything to do with Camera House not carrying Pentax, nor are they a general indication of Pentax reliability (though it might be comforting to think so). The vast majority of members here would, I'm sure, tell you that they've had mostly trouble-free service from their Pentax equipment - though a significant number of K-30 and K-50 owners do appear to have suffered the aperture control solenoid issue.
All brands have problems, of course - Nikon included. But, I wish you success and happiness with the D850 (it's a great camera, from the reports I've heard).
Good luck!