Here is what I know about handling an incorrect 1099-MISC --

First, you should contact the business that issued the 1099-MISC and ask them to send you a corrected 1099-MISC.
Keep documentation of these communications!
If you are unsuccessful getting a satisfactory answer to the discrepancy or getting them to agree to send you a corrected 1099-MISC, you will need to call the IRS at (800) 829-1040. It’s best to do so early in the morning, since you’ll have a better chance of getting through.
Explain that you received the 1099 and disagree with the amount that was reported on it, and that you’ve tried to resolve the situation with the business, but have been unable to.
Ask the IRS complete a Form 4598, “Form W-2 or 1099 Not Received or Incorrect.” (You have to request it via this phone number and IRS must complete the form -- It’s not something you can just download from their website.)
You’ll need to give the IRS the payer information from the 1099 you received and the details of how you arrived at your own valuation figures. The IRS will send the complaint form to the business, who has 10 days to respond (you should receive a copy as well).