oops! 3 month visa expired...whats the penalty?

I was supposed to leave town on the 3rd, but when I got down to Buykebus, was madness... 3 hour wait & 250 pesos to Colonia... I fly to Europe Wednesday evening...., but will be coming back to town end of February. Can I take care of this at the airport? Small fine?
Thanks for the educational link...however, you might want to reply with something having to do with the original question. Lee
Thanks Lee. I have heard around 50 pesos or dollars...both fine. Do I pay at passport control, or do I go to some "special" place in some distant corner of the Airport? If the latter, does it take long...?
I thought, Lee, that Elpa' meant her link to comment upon the unpredictability of what the Argentine government might do. Or perhaps she intended otherwise. Who knows?
I have to agree with Lee. I I wanted a history lesson about the "Dirt War"... I would probably have gone to Google. I do enjoy history, but at the moment I have other things on my mind...