Regarding your 2019 tax return - the IRS probably still working on that, so any AGI you'll put there won't be correct. The IRS pays good interest on amounts that weren't timely send, you will eventually receive your money plus interest. You need to print and mail your 2020 tax return and the IRS will investigate who claimed your dependent. Unfortunately, it will take time. You call the IRS customer support number at 1-800-829-0922 or 800-829-1040 and report the issue with claiming your dependent.
