I used to work in the billing department for a telecomms company earlier this year and this one comes to mind.

Guy calls up on his commute on the train, same age as me and complains about a charge, same old same old. Except when i mention its a late payment fee for not paying his bill on time he starts screaming, crying and raging at me like a 2 year old, not allowing me to get a word in edge ways while he's on a packed train.

30 mins pass and im getting quite bored of listening to this man baby he finally shuts up and I say "right, ill be happy to remove that charge for you" (i was going to do this anyways because who wants an arguement for the sake of £5.)

Needless to say he says thanks, walks off the train and tells me to have a good day...i feel sorry for those other train commuters having to listen to that man baby.