As far as I am aware, not receiving your W-2 by 1/31 is not the basis for a lawsuit.
There are a number of possible reasons for not receiving a W-2, including that it was lost in the mail. If you still haven't received it, the first thing you should do is contact your employer and notify them again that you haven't received it. Verify that they have your current address. Determine if there is another way to receive it (for instance, by email).
If you do not receive the missing or corrected form by February 15th you can call the IRS at 1-800-829-1040. Be prepared to provide your name, address, phone number, social security number, dates of employment and your employer/payer's name, address and phone number. The IRS can use that information to contact the employer for you and request the missing form. They can also send you a Form 4852 (Substitute for Form W-2 or Form 1099-R).
If you do not receive the missing form in time to timely file your tax return, you can use the Form 4852. If you receive the missing or corrected Form W-2 or Form 1099 after you file your return and a correction is needed, use Form 1040X (PDF) (Amended U.S. Individual Income Tax Return).
Answers to questions are meant to be general only, are not intended to be legal advice and do not create an attorney-client relationship. Answers to questions are based on NY law, and the laws of other states may create different rights and obligations.