the IRS has instructions on what to do if you receive an incorrect W-2 and the employer is uncooperative: https://www.irs.gov/faqs/irs-procedures/w-2-additional-incorrect-lost-non-receipt-omitted/w-2-additional-incorrect-lost-non-receipt-omitted
That said, what is incorrect about your W-2?
You can include Form 4852 in your tax return with the correct W-2 information. Normally you would first contact the IRS, as described at the link that Hal_Al posted, and they would send a letter to your employer. But since the IRS is essentially shut down right now, just go ahead and file with Form 4852.
When you enter your W-2 in TurboTax, enter the correct information instead of what's on the W-2 from your employer. After you click Continue on the W-2 entry screen, you will get a screen that says "Do any of these uncommon situations apply to this W-2?" (There might be some other questions about your W-2 information before you get to this screen.) One of the boxes says "Substitute form - I didn't get a W-2 from my employer and need to complete a substitute form." Put a check in that box (even though that's not exactly your situation) and click Continue. The next screen asks if you want to complete Form 4852. Click Yes. Proceed through the screens, entering the requested information to complete Form 4852. It will ask you to enter an explanation of how you calculated the amounts that you entered, and an explanation of what you did to try to get a correct W-2 from your employer.
Just a heads-up warning. You best be *ABSOLUTELY* *POSITIVELY* *UNEQUIVOCALLY* *SURE* that W-2 is wrong. Otherwise, it is you who will pay the price in the end, and it will not be cheap.
In my *very* *limited* experience of claims such as yours, more than 99% of the time the person making the claim is wrong. You've not provided any details on why you believe your W-2 is wrong, so it's impossible for anyone to really help you with this in a viable manner.
However, if the employer is refusing to change it, that's most likely because the employer is right and you are the one who is wrong. The reason I say this is because when you report anything other than what is on your W-2, you also have to show "reasonable effort" to get the W-2 corrected. Then if the employer does not correct it, it is the employer that will pay some fairly hefty finds in the end. Rest assured you're employer knows that. So that's why I question your dissertation that your W-2 is wrong when stated in conjunction with the employer refusing to correct it.