What is causing iPhone 6 to not work properly?

All of a sudden today when I use my phone the touch screen is all over the place....As I type a text other keys are getting hit that I didn't press, apps open without touching it. Apply store said do a reset, if that doesn't work erase all data and start as if it's a new phone. I don't think this is a software issue, it appears to be an issue with the screen. Anyone have luck with Apple on this? My phone is 4 months old, no damage, no water.