I would leave it alone. Life is too short. After all, UA did give you what you asked for.
Would you do anything in this case which actually did happen to me about two years ago? I was given an op-up to NC TPE/SFO which was very common during the summer peak season. After I boarded, GA announced overhead that they needed volunteers. They offered $600 VDB travel credits which I jumped immediately. We were told to take our carryons and wait at the boarding gate. A few minutes went by, GA thanked us for giving up our seats. I wanted to confirm the compensation of $600 VDB travel credits. He informed us that they were doing UG to NC on CI in lieu of VDB. I then demanded my seat back since this was not the same as announced earlier. To my surprise, they already gave away my seat. Since NC was a lateral move for me, I demanded the $600 VDB as originally offered. GA then agreed to give me NF on CI instead of NC. Which was not what I wanted to hear but reluctantly accepted. Adding salt to the injury, when we were waiting for our luggage at YVR, I overheard several PAX received not only the UG, they also received the $600 VDB as well. Of course, it was too late for me to demand equal treatment. My original 12-hour non-stop flight ended up being 16 hours with a connection at YVR. I arrived SFO 4 hours after the original UA flight. So I promised myself I would never volunteer this route again. Instead of enjoying my NF on CI, I was fuming the entire 10+ hours, which was really stupid. UA did give me op-up NF YVR/SFO which made it more palatable. The lesson learned here was if I did not know exactly what I would get in return for volunteering, I would stay put. I had much better experiences with other UA VDB since the TPE incident.
[This message has been edited by ecmt (edited 07-28-2003).]