Not very funny joke

A man joined a big Multi National Company as a trainee.

On his first day, he dialed the kitchen and shouted into the phone:
"Bring to me a cup of coffee, quickly!"

The voice from the other side responded:
"You fool; you've dialed the wrong extension! Do you know who you're talking to?"

"No" replied the trainee.

"It's the Managing Director of the company, you idiot!"

The trainee shouted back: "And do you know who YOU are talking to, you IDIOT?"

"No!" replied the Managing Director angrily.

"Thank God!" replied the trainee and put down the phone