I received a CP2000 for my 2021 personal taxes. A 1099 issued in my name rather than my corporation. Corporate taxes filed including this 1099. How can I fix this?

I filed an amendment in May with Turbo Tax and mailed that to the IRS TWICE in Kansas City.  Received another notice on Friday that this money is owed for this 1099. What do I do? How can I fix this?