I did tech support for a while and (besides the 'normal' strange calls) this one was the best ever.
Note: ... indicates his voice trailing off
Me: Hello, techsupport, this is Catananche. How can I help you today?
Man: Yes, I have a problem with my wireless modem...
Me: Yes? What seems to be the problem?
Man: I ordered a wireless modem...
Me: Yes? <thinking "Give me something to work with please!">
Man: It has wires and I'm really upset about it!
Me: <he's gotta be kidding me!> Sir, the modem needs wires, it's made so you can use your
computer without wires. It's really neat!
Man: NO!!! A WIRELESS MODEM DOESN'T HAVE WIRES! IT'S
WIRELESS!!!!!! I WANT A WIRELESS MODEM!
Me: I'm sorry, but <my company> doesn't have wireless modems, we have modems that can be used for
wireless internet. I can help you installing the modem you have?
Man: NO! WIRELESS!!!! WIRELESS!!! WIRELEEEEEEEEEEEESSSSSSSSSS!!!!!!! <click>
Me:

What did just happen?