One of the more annoying customer complaints I had came on a Chateaubriand. The customer wanted it well-done but not charred, for starters.
The Chateaus we served were cut from a very large section of a pretty good sized tenderloin, so of course I groaned at the 1/2 hour it would take to cook it. I did cook it to his specified temp (and verified with my Thermopen) only to have him send it back as too well done.
I advised the server I'd make him a new one but it would take another 1/2 hour. This time I sent it out MW and he loved it.
At the same place I had a server ring in an order for a med-rare 12 oz sirloin. She warned me that the lady told her she often sends the steak back a couple times because she's picky about her MR. I procede to cook it to the specified temp and send it out; predictably it's returned as not done enough. I cook it (yeah, the same steak) a bit more, same result. After about 4 times it's MW, verging on Well, and the customer is delighted. This demonstrates that the customer isn't always right, is sometimes an idiot, and also that she'd have better luck if she had even the faintest idea what temperatures mean before she just pulled one out of her ***.