Since i started this job, I had work 80+ hours every 2 weeks for a year. But when i recieved my W2, It shows that less than half of the hours were reported. What do I do?

I have the timesheets that have the correct amount of hours I worked. But my W2 I just recieved from my employer says I only worked a 1/3rd of what my timesheets say. Is this lawful?