The Non-Existent Doctor's Appointment

I've just had a very odd phone conversation...

Doctors Receptionist: Hello Dr Stewarts clinic...

Me: Hello, I recieved a letter yesterday to tell me I've got an appointment for this afternoon at 4:30, I'd like to cancel it please.

Doctor's Receptionist: Why?

Me: Well, it was such short notice and I can't make it.

Doctor's Receptionist: What name is it?

Me: (give my name)

Doctor's Receptionist: Oh yes, it's already been cancelled.

Me: When?!

Doctors Receptionist: This morning.

Me: Well it's a good job I've just phoned isn't it?

Doctors Receptionist: Why?

Me: Well, because I would have turned up to a cancelled appointment.

Doctors Receptionist: We did send you a letter.

Me: When?

Doctors Receptionist: This morning

Me: What, by owl?

Doctors Receptionist: Excuse me?

Me: The appointment was this afternoon and you sent me the cancellation letter this morning. It wasn't ever going to reach me in time, unless you have magic stamps. Do you have magic stamps?

Doctors Receptionist: Doctor only realised his clinic was full this morning, he's tried to get intouch with you.

Me: How, by telepathy?

Doctor's Receptionist: You were ringing to cancel anyway.

Me: Thats not the point!

Doctors Receptionist: It's been changed to Monday now, so we'll see you then. Bye.

Me: Aaaargh...! Bye then.