I recently qualified as DL Silver Medallion. I have a flight this coming weekend on NW (ticketed NW), and as part of my SkyTeam elite partner benefits have been trying to get preferred seating on my NW itenerary this weekend. I went online and updated my SkyMiles number (several times) on my NW itenerary to hopefully pick up my new status to no avail.

1st call to NW agent: Call DL and have them go into the NW record and update your status as elite.

1st call to DL agent: I can't get into your NW record. Call NW back and have them assign you the seats anyway.

Next day

2nd call to NW agent: I'm sorry, but your SkyMiles number is not coming up with status, you need to call Delta back and work it out with them.

2nd call to DL (agent answered as a Medallion Services agent): You can only get preferred seating on NW if it is a codeshare flight (!). I said that I didn't think that was right. We went around in circles until I heard her say that NW isn't part of SkyTeam(!). She then went on to list SkyTeam members beginning with Alaska (I immediately knew this was wrong as I am also an AS flyer) etc. I told her that she needs to study up on her SkyTeam members at which point she put me on hold and I hung up.

Now, am I wrong to think that my status on DL allows me preferred (partner elite) seating on NW metal and NW ticketed flights?

If I am not wrong, how in the world am I going to remedy this after 4 phonecalls and about 10 resets of my skymiles in the NW system? The DL system shows my status and I have been able to request upgrades and make preferred seating choices.

Help!