I'm not being fully paid on a residential project. I reached out to the owner of project and advised a lien would take place. I was advised a full lien waiver was signed by GC on job. The GC did make a partial payment to us but we never signed a waiver or was even asked to sign one. The owner basically told us there is nothing we can do to them and they aren't paying any thing. That we need to work it out with GC as they have been fully paid. How do I proceed now?