I worked for a company that failed to pay me, but received a W2 saying they did.

I worked at a large national fast food company for about a week and did not receive a pay check.  I was told it would come, but never did. I asked again and no luck.  I couldn't afford a lawyer to sue them so I forgot about it.  So now I get a W2 stating that I received a pay check which according to my checking account was never deposited.  What do I do now?