My previous company withheld taxes from my pay. Let's say I was supposed to be paid 10,000, but they withheld 3,000 for tax, medicare, etc (or at least paid me as if they were withholding), so I ended up with 7,000 in pocket. But instead of getting a W2 that shows the withholding, I got a 1099 saying I was paid 7,000 without any witholdings, and they told me they haven't paid the IRS any of the missing 3,000. What should I do?