Group Messaging Option missing
I'm running iOS 6.0.2 on iphone 5. I can send MMS, SMS and iMessage. The issue I'm having is that when I try to do a group message it only works if everyone is apple (iMessage). If they don't, then I get individual replies. I'm with ACS in Alaska and they are only 3G. I had AT&T LTE about a month ago and had that option to click Group Messaging in settings and it worked great. I no longer have that option in settings at the bottom of the messaging section. It only has the MMS, subject line and character count options. Any ideas on how to fix?
iPhone 5, iOS 6.0.2