I am a homeowner in CA whose contractor has not paid his material supplier. I do not want a mechanics lien on our house. We paid the contractor for the supplies as he said he needed that money to pay for them up front. The invoice from the supply company indicated payment was due COD. Since everything was delivered and left assumed this was paid and the supplies were used. The material supplier left a note 3 weeks later at our house for the contractor indicating a mechanics lien was possible. When I called the material supplier they said our contractor owed them for three additional jobs. It seems wrong for them to keep delivering supplies COD, when the contractor has not paid them for past jobs and then threaten the homeowner who has already paid the contractor. Do you offer advice on this?