Who's That On The Telephono?

Telephone Operator "Number please."
The Prisoner "What exchange is this?"
"Number Please."
"I want to make a call..."
"Local calls only. What is your number sir?"
"I haven't got a number."
"No number, no call!"
{Suddenly there is crackling on the lines, and a distant voice}
"Hello, hello, are you there caller?"
"Hello, Fotheringay?"
"Look who is this?"
"Peter Smith."
"Who?"
"Peter Smith."
"Never heard of you."
"ZM73."
"What's that?"
"My code name."
"Its it?"
"Don't you know that it is?"
"No."
"Do you recognise my voice?"
"I........well there is something familiar......hello old man!"
"Fotheringay I need to talk to the Colonel."
"He's not here old man. I say you created quite a field of chaos when you resigned."
"Did I?"
"It was complete pandemonium. Where are you?"
"I don't know!"
"Don't know. Look are you alright old man?"
"Look when the Colonel gets back get him to call me..........hello Fotheringay!"
{Crackling on the line the voice fades}
"Fotheringay, are you there?"
"Number please?"
"I was just cut off."
"What was the number sir, I'll try and reconnect you."
"Whitehall 1........."
"Local calls only sir. What is your number?"
"I haven't got a number."
"No number, no call!"
{The phone goes dead}