Good luck. I tried several times. I moved to DEN back in March from STL. I was gold with AA, and Silver with US. They wouldn't budge. A fax and a few flights later I'm premier with UA.
I wound up writing a very nice courteous letter to the CSA department explaining the amount of flying I do for business. How AA received the bulk of that business and how they could tell by looking at my record that I always used them to get to DEN from STL when I could. Even had the credit card.
The response I got was, in short, "our program is great, we don't need to match because our program is great, and cheer up, you'll be there in no time".
Sort of OT, but I also mentioned that the availability of award travel was less than stellar and one of the main reasons I wanted the upgrade was to be able to utilize the higher redemption levels whenever I wanted. You'd think that at 8,000 miles left to go to reach Ascent that they'd just go for it, letting me blow 30,000 miles, in the hopes I'd give them my business. I'm now 5,000 miles away, and thanks to their attitude, the bulk of my flying has been on UAL.