I got back a little over $1900 about 2 years ago. The irony is it was money I had already paid to the state for sales tax in 2007, showed the DOR guy the cancelled check and bank statements proving I had already paid, but was forced to pay it a second time because the asshole didn't wanna listen to reason.

Took 9 years to get it back...with no interest and I couldn't charge the state all sorts of ridiculous penalties, either.

I'm happy I got it back thru the "payback" website but it should've never been taken from me in the first place. So it does work. Be prepared for a long wait, though. Took about 4 months.

ETA: It's definitely legit.