I've had the 5S since launch. I constantly see the "screen door" effect on my phone - faint but visible vertical lines appear on the display. I've taken it to the Apple Store twice, but they apparently "can't replicate". It's something that's difficult to explain but its a legitimate issue. I've seen hundreds of other people posting about the same thing. Is there anything else I can even do at this point? I paid a lot of money for this phone and its defective.