Hello and thank you for your time.
I have been you using a samsung S6 model dor the past 2 years and it worked great but recently I wanted to clean it up and did a factory reset using the vol+power+home key combination and it was fine until i realized i can no longer reply the text messages i recieve i checked the messaging center and it said "Not set". I called the my service provider asked about the messaging center number and tried to configure it back. But my phone keeps giving me a "unable to set messaging center" notification whenever i do so . Tried wiping the cash partition did another factory reset, tried deactivating and reactivating the app nothing works ○_○'