I called one of the main 800 numbers, system recognized me quickly, told me (complimentary) upgrades were requested for my 2 flights next week, in reply to the question as to why I was calling I said “Advantage Customer Service” (CS), of course the system didn’t recognize it (the first time and I only give automated systems 1 try), I pressed “0” repetitively, they offered to call me back in 10 minutes which was relatively accurate. A human picked up quickly, I requested “Advantage Customer Service” (CS), then maybe 3-5 minutes hold until CS picked up.

The first CS rep was clueless (as above), I asked for a supervisor or manager, 3-5 minutes hold during which the first rep came back on the line after 2-3 minutes to tell me he was still holding for a supervisor. Supervisor was excellent (as above).

It's possible that if the automated system recognizes “Advantage Customer Service” you might get routed to CS immediately.