the_hef:
I feel sorry for you and your plight, but is it really necessary for you to post your "I made a mistake but they owe me...." message to so many news groups (NG). I think this is called spam for obvious reasons, and a complete waste of valuable bandwith. Posting to the Northwest NG should of been totally sufficient.
Since you are a CO PT, you must have sufficient FF miles in your account to get your cute child his/her own business class seat, with real seatbelts to anchor your FAA approved child seat, etc. You, your wife and your cute child will enjoy the flight so much better this way, and so will your fellow passengers in business class. That is what I have always done in the past when flying with my cute child(ren).
Another suggestion is to buy at least one share of NW stock and express your plight to the actual owners of this airline at the next stockholders meeting. Tell them they will lose your future business (they already lost mine) and your cute child's business when he/she is buying flight tickets.
I am now going to check the Hilton and Avis NG. Oh, I hope, you didn't post your plight there too. The readers of those NG probably can't assist you either.