OP: I'm just curious if this happened at the Apple Store in Ann Arbor. Its very similar to an exchange I had with a genius.
My advice is to just chalk him up to a bad apple and try again with a different genius or at a different store.
I had a light leak through the back plastic of my white phone, and felt that to be unacceptable. Went to the Apple Store, and the genius was very confrontational and at first refused to exchange. Said the same thing about me returning too many phones due to poor quality control. I was firm, but polite, in my insistence that this wasn't acceptable. He kept trying to say that it was "within spec." Which, imo, is bs. Ulitmately, he did exchange it, and the replacement has the same problem.
But, I went to a different store, explained the light leak, the genius took it in the back to check it out in the dark, and came back with a replacement. Easy as pie. He said that it was very strange and should be replaced.
So, the moral of the story is that a) you are entitled to as many replacements as are neccessary to get it right. Apple isn't responsible for the condition of your phone months down the line, but within the first few weeks it shouldn't have the many problems people have encountered. And it should never have dust under the screen. b) the experience at the genius bar is contingent upon not only your attitude, but that of the Genius. 99% of my experience has been absolutely amazing, but there's always that 1%.
And, there should absolutely never be any rattling when you shake your iPhone. Anyone that thinks that is being ridiculous.