Can I go after H & R Block for tax errors that they caused?

I went to H & R Block to have my taxes done in January of this year. I've never owed money or been penalized for anything, but now I'm getting letters from the state I live in telling me I owe them a lot of money with interest and penalties. H & R Block told me that I only owed Federal that I already paid in February. They are claiming that they are not responsible. had an amendment filed by a MANAGER because of errors done by the original preparer. I've been giving until 7/1/2011 to have this money that I didn't know I owed to be paid in full or it will continue to add interest and penalties. I did not buy a peace of mind because I was lead to believe that I didn't need it because my taxes were done correctly. They are refunding me my tax prep fee and the interest, but I have to pay hundreds out of my pocket that I don't have. If I had time I could have saved up the money and paid them before the April deadline. They lied to me and made mistakes on my taxes and they aren't owning up to there mistakes.