So OP got the fare difference + 3000SM (= $30.00 if used for PWM)? That is just plain insulting. Sorta like giving a valet at the hotel $.25 for a tip, except in this case the insult is to the customer. I am pretty agreeable in most instances, but I would be livid over a "resolution" like that.
If any staff at DL is monitoring FT, DL needs to step up and make this one right.