In Truestone, Inc. v. Simi West Industrial Park II (1984) 163 Cal.App.3d 715, a property owner (Atoian) entered into a construction contract with Vista. Vista purchased certain construction materials from Truestone that were used on the project. Vista allegedly failed to pay for the materials. Truestone filed suit against Vista and Atoian. As to Atoian, Truestone alleged several claims, including unjust enrichment. The trial court granted Atoian's motion for summary judgment. (Truestone, supra, 163 Cal.App.3d at pp. 718-721.) On appeal, in reviewing the propriety of the trial court's ruling that Atoian was entitled to judgment as a matter of law on Truestone's unjust enrichment claim, the Truestone court noted that in Earhart v. William Low Co. (1979) 25 Cal.3d 503, a contractor was entitled to recover on an unjust enrichment claim because the defendant made an "express promise to pay the contractor. . . ." (Truestone, supra, 163 Cal.App.3d at p. 724.) The Truestone court noted that Truestone's complaint contained "no allegation that Atoian promised to pay Truestone, or that Atoian did not pay Vista." (Truestone, supra, 163 Cal.App.3d at p. 723.) The Truestone court reasoned: "Truestone, by contrast, alleges unjust enrichment in conclusory terms. It now seeks to rely on an oral promise by Atoian which the complaint does not allege. The allegations of counter declarations may not be used to compensate for defects in the complaint. The counter declarations on a summary judgment motion ' ". . . may not create issues outside the pleadings; are not a substitute for an amendment to the pleadings; and are an ineffective defense to the motion unless they 'set forth facts showing that . . . a good cause of action exists upon the merits.' ''