Me: I can receive texts from NZ and Germany, but not from US.
CSR: Try taking the battery out for 15 minutes.
Naturally that didn't help at all.
To be fair, I should also admit the time when I completely misinterpreted a request. I was having trouble with a brand-new AirPort base so I called AppleCare.
Apple: Are you using a cordless phone?
Me: No, but I can switch to one if you like.
It's blatantly obvious now that he wanted to make sure that there was no interference from the phone, but I interpreted it as "are you able to walk around the room?" (for testing the Wi-Fi)
And for closure: The AirPort was defective, Apple replaced it and the new one is still chugging along happily now, six years later!