Greatest gift ever from the comedy gods.
Listen to the audio before you read this attempt at explanation:
Near as we can figure, a guy gave her a fake number some time over the course of a steamy romantic evening. But the number was either a random creation or a number he had on a card in his pocket — which would mean he somehow knew us. Anyway, when she woke up to discover loverboy was gone, she called the number and got the voicemail, which announced itself as the offices of Duncan/Channon, which she took to be the real first and last names of lover (who no doubt gave her a phony), who she proceeds to excoriate — to delightful effect.