Glitches I phone5c or iOS7? (keyboard and contact names)

With in 30 days of purchase, my I phone 5c had certain glitches. When I went into my messages my keyboard popped up but not the letters or numbers. So I pressed the home button and it fixed. Two weeks later it happened again but I pressed the home button 3 times and did not fix. Then I'm sure I shut the phone off and it worked after that. That same day I called apple they made me do the reset(holding lock & home button), I erased all my extra pages they said it should be fine. The next morning after charging I saw my banners and it was just showing my contact numbers and not the names. I went into the messages and,same thing. when I pressed the home button and went back in, it was fine. I'm not sure if this just happens when a phone gets worked up but I need too know before my dead line is up so I can trade it in for a new phone.