Originally Posted by clarence5ybr
I've had DL agents tell me that once flight activity has taken place on an itin, the FF# can't be pulled. This even applied when I wasn't trying to change to a different program, but rather to get my SM# pulled from a PNR and then re-entered so that my change in Medallion status would be reflected.
Well, looks like you got one of the (now many) agents not knowing their stuff. It certainly can be done.
What DL can't do by the book is remove your Skymiles number if you're using their complimentary Medallion Elite upgrades.
On NW, it is a different story. Their system and gate agents are perfectly able to handle upgrades based on eligibility AND mileage credit based on personal preference without any problems. Of course, I am always nice and friendly to the agents, which might help the fact
Now, if NW's phone reps were as friendly as their ground staff, they would get more business from me. But they are the worst in the industry, often lack common courtesy, and that's where I had confirmed (mileage) upgrades taken away.