Iphone 6 Shutdown and randomly turned on 20 minutes later- nothing to do with text bug

My iphone 6 shut down randomly yesterday (no text messages with the code that shuts off iphone), and it would not turn back on no matter what I did (hard reset, one button, two buttons, all buttons held). I plugged into my Macbook air via usb, then alone on charger, but nothing would work. Then 20 minutes later it turned one last try at a hard reset before I went to the apple store. This is the second Iphone experience that is making me think of switching to Samsung. My Iphone 5s ended up dying within one year warranty, replaced by a new/refurbished one at apple store, then blue screen of death to that phone which happened outside the warranty window. What the heck is happening with Apple. I can't believe such a trusted brand is having so many issues. Once I could understand, but three phones?! Apple, please get it together. I don't want to jump ship but I will if I have anymore problems.