I'm at 27469 points, one point shy of a promotion. No matter how many times I shoot opponents down, bomb destroyers and airfields, etc, every time I reach 27470, I won't get promoted and my score keeps going back to 27469.

Have you tried landing at your base while you have 27470 points?

Yeah, landing at base and reloading is the key, it often doesn't update your rank until you reload or the games ends.

The game has always stopped accumulating points when you reach the upper limit of the rank. Recently it seems you actually have to exit the game and start a new game for the promotion to occur. Previously, you could reload or parachute and it would promote you in-game.

Zup has a lot of fixes when he get back.

Lately it won't show the gold letters unless you uninstall then reinstall game on your device.