What is the movie called where a little boy gets taken while talking to his mother on a walkie talkie Then the mother looks for the boy and suspects her violent ex husband?

The movie you're referring to is "The Call" (2013). In this thriller, a mother engages in a desperate search for her kidnapped son after he is taken while communicating with her via a walkie-talkie. As she investigates, she grows suspicious of her violent ex-husband's involvement in the abduction. The film builds tension as she races against time to save her child.