So I've had this phone for like 5 months now. 2 days ag, I'm always textin my friend John and I've never had a problem. But 2 days ago John couldn't recieve my text messages but I could recieve his & this problem is still going on. Buts ONLY to his phone, I have no problems texting other people. Do you think its my phone or his phone? What do I do to fix this problem? HELP PLEASE!