Unfortunate issue. I'm not sure I have the knowledge to provide a fix, likely a moderator discussion, but I might be able to help you get more information.
1) Log in to your "My Account" --> "My Plan" --> "View My Usage" This should give you a complete lot of incoming and outgoing calls and text messages. Confirm that you are seeing the outgoing, confirm if you see any incoming.
2) Open you phone and send a text message from it to it, this should send the message directly back to yourself effectively a basic loopback test. Did you recieve the message?
3) "View My Usage" again, if you see both the outgoing (phone to system) and incoming (system to phone) then the system recorded the transmission to your phone and I'd guess the issue lies with the phone itself. If there is no incoming I'd defer to moderators and people who know cellular networks a whole lot more than I.
*Folks who know cellular networks better than I: If this troubleshooting is inherently wrong let me know being wrong helps me to learn things and no feedback helps nobody.
