Text messages from one contacte associated with the wrong contact in message app in iOS8

I am having a problem that I and the folks at my local Apple stores can't solve. A text came in from a friend on the menu screen (let's call him Contact 1). When I tapped on the message, I was directed to a completely different contact and her thread of messages. The messages from Contact 1 also appear to have disappeared and I cannot retrieve them. I have tried restarting the device, I have tried resetting the device. Nothing I have tried works and the folks at the Apple Store have know idea what the problem is - they have never seen anything like it. I'm going to try upgrading to 8.4 but any feedback would be greatly appreciated.