Maybe contact offices in the USA and they can help and give you a POC in Buenos Aires. Big outfit and they may be reluctant to help the little guy.
"Acceptance Agent (AA) or Certified Acceptance Agent (CAA)
There are two kinds of Acceptance Agents:
Acceptance Agent (AA): authorized to assist resident and non-resident alien individuals and other foreign persons ineligible
or unable to receive a social security number (SSN) in obtaining an ITIN or Employer Identification Number from the IRS. They
review the required supporting identification documentation that proves foreign status and identity, verify the completeness
of the application , and forward the Form W-7/W-7SP with any required supporting documentation to the IRS.
Note:
The ITIN assignment letter is sent directly to the taxpayer, not to the AA.
Certified Acceptance Agent (CAA): in addition to assisting resident and non-resident aliens and other foreign persons ineligible
or unable to obtain a SSN, they are authorized to submit a Form W-7/W-7(SP) without furnishing supporting identification documentation.
The CAA substantiates the claim of identity and foreign status, authenticates the accuracy and completeness of supporting
identification documentation, and attaches a Certificate of Accuracy (COA) on office letterhead stationery. This COA identifies
the type of supporting identification documentation that was reviewed and is forwarded with the Form W-7/W-7SP along with
any required exception documentation to the IRS.
Note:
A CAA is permitted to receive the ITIN assignment letter directly from the IRS."
