I had the same situation a few years ago, posting 24,968 miles after 12 straight years as 1P or 2P. When UA wouldn't make an exception I called AA and flew them for a year on a status match. Of course the geniuses at UA then send me an invitation in May to overlook the 32 missing miles and offer me 2P status for the rest of the year. At that point I already had flown 21,000 miles on AA, on my way to 50K for the year. Not wanting to miss the 1P status for the following year, I explained to UA that I would be happy to spend my money with them for the rest of the year, if they acknowledged the 21K miles I had already flown so I would be back at 1P status. Otherwise, I explained, I would have no choice but to spend the rest of the year buying AA tickets. Guess what UA decided to do?

Needless to say, I spent the rest of the year in the back of the AA MD-80's. Little wonder that UA is in such a financial mess.