I had an issue with people trying to send iMessages to my phone number.
for some reason ios7 had set iMessages to only send to my email address and not to my phone number.
to fix it, I had to get the help from my boss at work :)
its an easy fix:
go to settings > messages
scroll down to ‘send & receive’
go in to ‘send & recieve’
click on the ‘apple ID: email@example.com’
click sign out