That is an interesting story, but it isn't really even close to what happened to the OP.
What happened to the OP would be like:
Ever had your airline 12th row window seat change to row 32 middle seat?
And you didn't find out until airport check in?
And then the airline gave you a written explanation, admitted the error, apologized and changed things so you were reassigned to your 12th row window seat?
^^^THIS is similar to what the OP experienced. The error was caught, fixed, and apologized for. Any funds charged were promptly returned. The OP was given the cabin they happily booked in the first place.
Another similar comparison would be if you had a 12 row window seat booked. When you showed up at check in, the agent tells you that they can upgrade you to first class if you'd like, and of course, you say "yes, please". Then, when the agent processes the upgrade, they say: "Oh, I misread the screen, we have no availability in first class. I apologize for my error. I've re-assigned you to your original seat." and your reaction is to seek advice on the internet on how to wrangle "compensation".