After updated to iOS8 update on my iPhone 5c, it no longer works. You can turn it on put in your security code and screen goes blank.
http://www.apple.com/support/iphone
This is where you need to address that device issue. Apple updated your ios to iOS 8 not Verizon.
Or walk into a Apple Retail Store and have them look at it.
Good Luck
Sachela, oh, no! We're stepping in to get you back up and running. Have you connected to your device to iTunes to restore your device? http://vz.to/1mKK2Zo Keep us posted. LasinaH_VZWFollow us on Twitter @VZWSupport