We have a contract to do work at a certain amount, and we performed the work. The general contractor and owner is now making claims about our work that we disagree with. Instead of paying us the full amount due, they are making "back charges" against us. We want to file a mechanics lien or something, but want to go after the full amount. When filing the mechanic's lien, can we still put the full amount due in our opinion? Or do we have to reduce our claim for the "back charges?"