2 hours is just plane ridiculous. 20-30 minutes okay max, but 2 hours, forget it.
I've take the same flight (to EZE) and the first thing you want to do is fall asleep since it's already midnight. Pushing it another 2 hours is just plain ridiculous.
I would complain complain complain.
I don't know what Operational policies are deployed, hopefully Andrew can pipe in when he's back.