About a month ago I switched from an iPhone 4 to the Samsung S4 and realized that I'm unable to receive text messages from my iPhone user friends. I figured trying to trade in my iPhone 4 to Verizon would help but I still have not been able to receive messages from most of my family and friends.This is very frustrating not being able to have a conversation because I cant receive a reply. I even un-registered my phone from Apple, deleted msg threads, and even had to tell my friends to turn off imessage and still nothing. HELP PLEASE!! I will take any suggestions.