CP268 tells you we made changes to your return because we believe there is a miscalculation on your return. Get free tax help from the IRS.File your taxes, get help preparing your return, help yourself with our online tools, find your local office – or call us. Below are instructions and sample calculations for garnishment writs as well as solutions and sample letters for salary overpayments. Use Form 843 to claim a refund or request an abatement of certain taxes, penalties, additions to tax, interest, and fees. For federal income tax information and forms, contact the Internal Revenue Service (IRS). Telephone Information Center. You can get in-person help at your local IRS Taxpayer Assistance Center. Call for an appointment after you find a Taxpayer Assistance Center near you. Get your refund status.