Not Even Effing Phonetic

(I am answering the phone at the front desk of the hotel where I work.)

Me: “Thank you for calling [Hotel]. This is [My Name]. How can I help you today?”

Caller: “I need to make a reservation.”

Me: “Great, I can definitely help you with that! What day will you be arriving?”

Caller: *scoffs* “Oookaay; guess I am a f****** idiot, then!

Me: *quite taken aback* “I am sorry, sir?”

Caller: “I said, ‘I guess I am a f****** idiot!’”

Me: *confused and not really sure how to respond* “Um… Sir, I’m sorry, but why do you think that?”

Caller: “You just called me a f****** idiot!”

Me: *shocked* “No, sir! I can assure you I said nothing remotely close to that statement!”

Caller: *sounding genuinely surprised* “Oh, you didn’t?”

Me: “No, sir, I did not! I just asked when you would be arriving! I apologize if that sounded like I said something else, but I can promise you I would never speak to a guest like that!”

Caller: *completely nonplussed and cheerful as if nothing happened* “Okay, then, I need a room with a king-sized bed for the 12th.”

(The rest of the phone call was normal, but I still have no idea why this guy thought would just nonchalantly insult customers!)