Since getting my Samsung S4 I haven't been able to send or receive texts from my parents. They both have an iPhone 4S. They seem to be the only people I'm unable to text. I've tried turning off iMessage on both my iPad and my old iPhone and it hasn't worked. I'm able to text other people with iPhones fine, just not them.

You'd think this would be a blessing but my mom keeps my girl during the day so I need to keep in contact with her.

Any other ideas? I'm sure the people at the AT&T Store would be clueless.