Is the company EIN the same? Is your SSN the same? Are the amounts different? How much did you actually get from them? If you got $1500 and one is for $800 and one is for $700 probably you'll find the EIN is different, meaning they made some change to their company during the year that required getting a new EIN.
If both are the same amount and it matches what you got, they just screwed up and sent the 1099 out twice. Don't worry about it. Just report what you know is the right amount and don't worry about the 1099.
If your SSN is different you may have signed up with them twice and made a typo on your SSN. In that case, let them know of the error. But just put the amount you know you got on your tax return and don't worry about the 1099. Those are more for the IRS's benefit than yours. As long as the IRS sees at least as much income on your tax return as they knew about from the 1099's, they won't bother you about it.