My pantech matrix c740 has a message stuck in the outbox?

My pantech matrix c740 has a message stuck in the outbox I've tried the master reset I've tried taking the battery and Sim out but neither of these work. any other suggestions?|||Well if none of those work then you might as well head to the AT%26amp;T store and ask for help. Maybe try turning your phone off and then on again and then delete the message in the outbox?