Losses of C-corporation are not passed to shareholders.
A corporation generally figures and deducts a net operating loss (NOL) the same way an individual does.
The same 2-year carryback and up to 20-year carryforward periods apply, and the same sequence applies when the corporation carries two or more NOLs to the same year. For more information on these general rules, see Publication 536, Net Operating Losses (NOLs) - http://www.irs.gov/pub/irs-pdf/p536.pdf
Yes - C-corporation would get refund for overpaid taxes after filing amended returns for last two years.
This is the form to use - www.irs.gov/pub/irs-pdf/f1120x.pdf
File separate form for each year and mark the years for which you are filing in the header.
Amount to be refunded should be on the line 12.