I have a galaxy s3 have had it for almost a year. About 2 month ago I noticed people not getting my messages. It is only AT&T phones I can't text. If I paying a bill every month for unlimited text messages I should be able to text whoever. Especially a man carrier like AT&T, i at the point of wanting to drop verizon and switch carriers. I have been have to use a texting app and my data just to text friends. Please help, it's starting to really bother me. Anyone know how to fix it?