Why do only about 1/3 of my text messages go through?

I recently purchased a Samsung vitality and for the past two months it has been working great but in the past 2 days I have had serious issues with receiving and sending text messages to the point where maybe 1/3 of my messages are going through and people are complaining that in not texting them back when I've received no messages. It is not my service I have almost full bars, I have already pulled the battery out and all that other pointless trouble shooting, I would like a factory reset to be the very last option. Does anyone have any ideas? If so please help.