macbook air won't charge & no light on charger

I charged 2011 Macbook Air yesterday and it was fine last night and again this morning. Then, when it was running low on battery today I plugged in the wall charger (which is a new one I got in July) and suddenly my screen went black and the charge light wouldn't come on. So, I unplugged the charger and then my screen came back. Plugged in charger again and screen went black again. I restarted my computer and still same problem. I even shut down and rebooted but same problem. Of course I didn't back up my files so I scrambled to transfer some to our portable hard drive but I was on reserve power and the transfer did not complete. So, now I have a dead computer. I even just tried the charger of a friend with a MB Air but her charger didn't work for me either. So, now I have just plugged my charger in with the hope that it will mysteriously start working again -still no light showing.

And ideas? I live in southern Mexico and closest Apple Store is in Mexico City...not very close to me :-(