You need to resolve that issue with the employer. If you received a W-2, that means that information was reported to the IRS. If you don't report it, then the IRS will send you a letter proposing an adjustment to your return. It will be much easier to resolve with the employer than the IRS. There isn't anything you can do from a filing standpoint other than not include it on your return, and then print and mail it to the IRS with a letter of explanation.