By the way, they should have refunded your credit card, not given you the difference in an MCO. ?
Well, my service with them has been good at times, and bad.
Rerouted serveral times, generously, in order to give me a first class seat when I was a silver member. Way to go CMH elite agents. Other good experiences, but nothing outstanding.
In the past month, however, it's been a bit egregious. Had an apparently new NW Perks agent insist that silver elite members (my wife) were not allowed to have preferred seating. Only gold and platinum. Really, I re-explained clearly, twice, that silver elites were allowed to select some of the first rows of coach. Said nope. I called back and the NW agent followed up, apologized and tracked down the other agent to correct. Said it was a new call center...
Several days ago tried to book a companion cert on NW. The cert, on the back said "full-fare ticket" which the agent insisted was a full Y. (Yes, I'd like to book an 1800 dollar ticket and pay 129 for my wife.)

As many of us know, this "full fare ticket" refers to the person paying the full ticket price. Not one word of "Y." Same wording, albeit vague at times, as we see on the NW and CO certs. So the elite agent asked the "rate specialist/supervisor" in Seattle, Kathy, and Kathy insisted that it is indeed a Full Y. Next day elite agent said that sometimes Seattle gets the late night elite calls and doesn't know what's going on. Okay.
Also, my impression over two years of with both NW/CO: with NW I find they, especially supervisors are "policy focused" and rigid when exceptions are warranted given individual circumstances. CO seems more "people focused" and thus I've had a numerous CO supervisiors listen and often find a fair rememdy. The former tends to treat rules as absolute, and the latter, as general. Indicative of managment philosophy. CO is wins in this respect.
JL2