I am a material supplier and filed a stop notice for a job with the County of San Diego and received the following message: "We have received your legal notice under Civil Code Section 9350 et Seq., dated June 19, 2020, claiming an amount due for work furnished to Prime Contractor (optional Power and Cable Solutions) pursuant to a public works contract. The legal provisions cited in this notice are not applicable, because the agreement between the County and Optional Power and Cable solutions was for a purchase of goods and not a public works contract." Also, A Third party company placed the order for the County, and the county installed the materials themselves. The county did not require the third party company to provide a performance bond. Was I supposed to file a lien instead of a Stop Notice?