If you are experiencing difficulties with the IRS, know your rights as a taxpayer. Read the Taxpayer Bill of Rights (https://www.irs.gov/pub/irs-pdf/p1.pdf). Also consider contacting the National Taxpayer Advocate service (https://taxpayeradvocate.irs.gov/contact-us). And you may want to engage a tax professional who can represent you in this matter.
Eligible taxpayers may claim a tax credit for 10%, 20%, or 50% of up to $2,000 of retirement plan contributions.