The customer said she would not pay me unless I signed a lien waiver, so I signed her lien waiver and then she refused to pay me. It turns out that the lien waiver she had me sign was an unconditional lien waiver, which I had never seen before. I'm owed almost $5,000.00 and she is no longer responding to any of my emails or phone calls. Can I still file a lien and recoup the money that is owed to me?