I received a 1099-B from my broker which I know is overstating my cost basis by $180. I requested a corrected 1099-B, but have not received one. My choices are to file with the currently incorrect 1099-B and if I ever receive the corrected 1099 then file an amended return or use the numbers that are correct and reduce the cost basis and run the risk of the 1099-B never being corrected. In the second case I will be paying more tax than if a corrected 1099-B is never issued.
You should file with the cost basis that you know to be correct. An incorrect 1099-B does not give you permission to pay less tax than you really owe. It is your responsibility to file an accurate tax return.
Follow the instructions in the post that Bsch4477 referenced to enter the correct cost basis in TurboTax.