You should always return someone's call.
Chris gets a call from a distraught friend while busy working on a project.
Chris wants to finish working on the project in time.
Chris apologizes and says he will call him back as soon as possible and calls back after finishing up.
Chris quickly gets off the phone and says that he has to work on something.
Chris' friend thanks him and appreciates his friendship more.
Chris' friend feels sad and alone.