Was laid off, was never paid my vacation time accrued. Does this sound right, or no?

So I was laid off and was recieving severance for the last six weeks. I thought I was supposed to get paid my accrued vacation time as well, but they told me that apparently when I first started working their, they pay you 80 hours up front so you dont have to wait four weeks to get your check? Ok. But now, they said that when I left, they subtracted that 80 hours from my vacation pay, and totally screwed me out of it.

Does this sound right, or no?

What if I took all my vacation days before I left? I saved them because I knew I was getting laid off and figured I could use the money, but now they are telling me that its washed out by what they gave me when I first started nearly five years ago.

Any advice would help. This is in Pennsylvania as well, if you need that information.