Yes. At the 45 day mark, I contacted Chase and requested a chargeback. I was told that Aerolineas Argentinas would have 10 days to respond to Chase and that if they didn't respond I would get the full amount refunded.

I never got a letter from Chase. I did, out of nowhere, receive an email from an accountant at AR. Written in Spanish, it still didn't make sense when translated to English: basically it said to immediately contact them if the request was made in error. A few days later, I received a refund on my statement from AR for a partial amount of what I paid (less than 50%). It was unclear if they just arbitrarily decided to refund me less or if it was due to currency devaluation (a major issue in Argentina).

Either way, it seems like AR never responded to Chase, so Chase had my back and has refunded me the full amount of the tickets.

I really think the customer service from AR is beyond abysmal and unacceptable for a SkyTeam member. AR sells refundable tickets but they seem to be only refundable in theory, and telling customers that it takes 120 days, or a third of a year, to do what reputable airlines can do in 3-5 business days is ridiculous.