These experiences reach a level of Zen-like perfection when you eventually get referred back to the first person you spoke to.
The Ouroboros complete.
Also letters on a slower circuit. I remember when my brother worked at Nationwide Life and this letter arrived complaining about how they had been asked to fill in the same form countless times. It said "I am sending this form again, this is your last chance keep it in your records and do not lose it, if I'm asked to fill this form again then you have lost me as a customer" - so he sent a reply straight back asking them to fill in the form. It makes you wonder how often those circuits and so on are naturally occurring and how often they are result of mischievous call centre workers. Incidentally he got fired from that job when he started laughing at a complaining customer on the phone. When they said "Are you laughing at me?" he quoted Shawshank Redemption (I think it is) "I'd laugh a lot more if you were sucking my dick with no teeth".
Another guy I knew who worked in a call centre and who discovered that he and one of his co-workers had a mutual love of The Fall, they passed the time by trying to get as many Fall references into their calls as possible, they would say things like "Can you read me your Hex Enduction Number?" and the customer would go "What?" and they would say "Your hex enduction number... or it might be listed as customer reference number on your contract".
This kind of thing is surely a natural product of employing bored, temporary, often over-qualified staff who don't give a fuck. It ought be be built into the model and calculated with like shrink is in a shop.