This has happened to my Impala. Same window, same problem. I bought a new switch on Ebay and it broke as soon as I installed it. Fortunately, I got a refund.
Thanks for the advice. We noticed that cleaning the contacts helps sometimes, but I've since just wedged a small piece of paper underneath the switch so no one can lower the window until I get it fixed. I've had a dealer tell me the motor has to be replaced...at the tune of $385. I know little about car repair, but even I knew if a window goes down, just not up, it isn't a bad motor.