@Roger **************
, she meant you didn't have enough TIME on your current stamp to apply for the in country Non-O visa at the CHiang Mai immigration office because they require 21 days minimum left on your stamp and you only had a stamp good until probably Feb 3 (if you stamped in on Dec 6th).
Had you shown up at the office to apply when you DID have 21 days left on your entry stamp you could have done it without the 30 day extension :)
You should have an extension good until about March 5, so that means you have to apply for this in country NOn-O visa by no later than the 12 of Feb to have the 21 days you need
Good luck, you're on the way to getting it (y)