Yeah it's stupid issue but extremely easy to resolve. My messages went to purgatory for about 15 minutes. http://phandroid.com/2014/04/07/turn-off-imessage-iphone-to-...
In the hopes of actually solving your issue, I hate to suggest this, but try reconnecting your number to imessage (and make sure you get any new imessage texts), then properly turn off imessage from that device. The defacto unplug it plug it back in.