I’ve Gotta Call You Back!

In this Slackatory supercut, we get to see a massive montage of people telling other people that they’ll call back…but then, they never seem to actually call anyone back. Why is that? Is “I’ll call you back” just a brush-off term in the world of the movies? I know that I always make a point to call back the people to whom I say “I’ll call you back.”