iPhone 4S- messaging issues?

I have the iPhone 4S through Verizon. It is currently running software version 5.0.1, which the updater says is the newest version.

I went to send a text message to someone I had already been texting and when they replied, it showed up as a new conversation rather than going into the one I was already engaged in with them. I erased the message I had just gotten from them so I had only one conversation going with then and I shut the phone off then turned it back on. Now all my conversations in messaging list the persons phone number instead of their name. This is the case with all conversations except the two that had the multiple conversations running.

Some of the numbers show the 1+ international area code in front of them, others do not. When I receive a text and it appears on the lock screen, it shows the name of the person but it is still listed as a number when I got to the actual messaging tab. All my contacts are still intact in the contacts tab as well.

I have already tried calling the Verizon *228 number and updating my phone that way and it did nothing.

You kind folks should help me out before I have to go ruin some Apple store employee's afternoon because my "superior Apple product" just took a dive on me. Please note that the quotes were used to denote sarcasm as I honestly don't much care for Apple products. I only got the iPhone because it was a little faster than the Android counterparts that the store had available.