Tonight the lady at the Genius Bar told me to expect my second replacement 5c to continue making a cracking and creaky noise when using the touch screen. She told me that since it's made of plastic and not aluminum like the 5S that it is expected. My first replacement was "captured" and I got a new retail unit. This time they gave me a replacement out of a white refurb box. The screen is creaky and loud. I'm so disappointed.