What I am getting out of this is that when a car is discounted because of its paint job, you don't buy it and demand a new paint job. However, they seem, by your own story, tried to make it right, even though I don't think many places would have done that. Switching stems is NOT a common practice except with a few odd makers who design for that purpose. But, I've never balked at oxidation in the first place. This is something we discuss quite a bit on here. Even with cars, you have to take care of the paint and plastic. Upon dredging through all of this, I would have just taken the refund with a smile. Well, actually, the oxidation wouldn't have ticked me off in the first place. I would have been happy with getting a pipe. But, even at that, it was a cheap pipe. I've dropped pipes that cost more than that into the river while fishing.
I think that the responses that you are getting are showing a failure to understand your issue. I thought I understood in my first responses, but re-reading this, I just don't get it. Sorry.