MarinaMaya

https://www.irs.gov/Affordable-Care-Act/Individuals-and-Families/Questions-and-Answers-on-the-Premium-Tax-Credit
Look at the last requirement. You can't get tax credit if someone can claim you as a dependent. (it's not whether someone claimed you but the fact that you qualify as a dependent). Please see the link on IRS website.
Who is eligible for the premium tax credit?
You are eligible for the premium tax credit if you meet all of the following requirements:
Purchase coverage through the Marketplace. Have household income that falls within a certain range (see question 6). Are not able to get affordable coverage through an eligible employer plan that provides minimum value (see questions 8 and 9). Are not eligible for coverage through a government program, like Medicaid, Medicare, CHIP or TRICARE. Do not file a Married Filing Separately tax return (unless you meet the criteria in section 1.36B-2T(b)(2) of the Temporary Income Tax Regulations, which allows certain victims of domestic abuse and spousal abandonment to claim the premium tax credit using the Married Filing Separately filing status (see questions 12 and 13). Cannot be claimed as a dependent by another person.

If you earned less than minimum amount you are not required to file at all.

Try calling again many times. don't give up.
They probably have your case number and IIN already.

Wife petitioned both parents at the same time and filed the I-864 with a household size of 3 for each form. NVC or the Embassy didn't have any issues with the I-864.
I got my information from the instructions for the I-864 page 5. Based on my understanding of the instructions Part 5 Item Number 6 implies that if the person has not immigrated already to the US then you don't consider them.

:thumbs: I stand corrected!