No, can't say I did. I always make sure to discuss the particulars of what the client is looking for in detail before I even agree to a commission, let alone actually start drawing anything. Something that I've learned over the years is to spend more time in the sketching phase, so before I spend too much time on the map, I'll put together a quick draft that has everything the final map will also have - a quick messy sketch of the drawing itself, labels, placeholders for things like borders and other decorations, etc. That way I have something very concrete to show them and say "okay, this is what the final piece will include, are you happy with this?" and make sure that we're both on the same page on what they are expecting me to do.

If the client ever was to request something else that was too difficult or weird halfway through the process, I would simply a) point out that that wasn't what we agreed upon, and b) give them a proper explanation of why I'm not able to do what they requested. Can't say that has ever happened, though.