First, Welcome to Flyertalk!

I was on the Delta flight ahead of you. We were the last to land in SCL. It was a 100% blind landing (IFR). We were in the clouds, then BOOM! We were on the ground. It was a first for me in my travels. The visibility was -zero-. The pilot said that rather than put the plane in a ditch he had "asked for a follow-me truck to guide us in". So we sat on the runway until a truck with a flashing light could guide us through the fog to the terminal! They close the airport shortly therafter, hence your diversion to Mendosa.

I've had some delays before, but 12 hours in Argentina, and not so much as a meal? I would be pretty upset as well.

Good luck, and again Welcome to FT.