@Randius, you said the sound was perfect? If so, this seems like a very small issue.
Of course, one is paying for more than sound and genuine build quality (in terms of reliability and sound production), as odd as it seems to say that. People pay to feel that what they have is special. Very minor appearance issues detract from that, leading to a feeling that what one has isn't worth the price, even if what the product is designed to do (produce sound) is unaffected.
So, email first. Send them back if you like, but let's not call this a "build quality" issue if it's not really about reliability and sound production--more like a very minor appearance issue.
Enjoy the music for a while before you send them back, though.