Here's the IRS's site that explains the CP14:
https://www.irs.gov/individuals/understanding-your-cp14-notice
You'll notice that under "What do you need to do" there's the point "Contact us if you disagree." That's about all you can really do here and they instruct you to "Call us at the toll free number on the top right corner of your notice. Please have your paperwork (such as cancelled checks, amended return, etc.) ready when you call." If the IRS has got something wrong here then you have to go to the time and effort to set them straight.
