I HAVE A BLACK SPOT GROWING ON MY PHONE

Is this common ?! I have an iphone 5!!! I know it's a dead pixel but I never seen this EVER HAPPEN! Ugh.. If I replace the screen will this happen again?! I'm tired of it! This black spot is the size of an American quarter!!! It also has yellow,purple,blue and green around the black spot and when I have a black wallpaper on the phone, it's a glowing green In the middle. will apple do something about this?! I feel like I'm the only one that has this!!