1. On 26 September, I contacted @LATAMAirlinesUS on twitter (via DM) asking for a status match (I did not specify level). Within minutes, I received a reply: "Hi. To assist you with the status match you requested, please give us your frequent flyer number for both airlines, birth date, e-mail address associated to the account and the last statement of this account. We'll be awaiting your response."
2. I replied with the information, as well as my statement and a pic of my status card. They promptly replied: "We created the case number [#######] to assist you with your requirement. Please reply to the e-mail we sent you by adding the information we requested there. We remain attentive to your comments."
3. I replied to the e-mail, which asked for: "- Latest account statement of your program account.
- Scanned or photographed copy of your elite frequent flyer physical card.
- LATAM Pass fequent flyer number (in case you do not have an account yet, you have to sign up first)
- Proof of a flight taken with LAN or TAM (now LATAM) during the last 12 months. This requires you to provide us with the flight information (Flight number, date, route) and either the reservation code or ticket number associated to it."
4. I replied with the requested information, though my last LAN flight was 18 months ago. I included the routes, fare codes, seats, and ticket numbers.
5. I received no reply, so on 8 October I contacted them in the same message thread on twitter. They replied courteously saying they were still processing it.
6. Having heard nothing, I replied in the same thread on 8 November, and got the same response.
7. On 28 Nov, I received a "Welcome to Black" e-mail, and my status was updated in the mobile app, valid through March 2019!