"`(O)n motion for summary judgment the burden was upon the plaintiff, as movant, to conclusively establish the absence or nonexistence of any defense. ...' [Cit.]" Scott v. Aetna Finance Co., 201 Ga. App. 81, 82 ( 410 S.E.2d 203) (1991). If the moving party discharges its burden, "the nonmoving party cannot rest on its pleadings, but rather must point to specific evidence giving rise to a triable issue. OCGA § 9-11-56 (e).

"`(O)n motion for summary judgment the burden was upon the plaintiff[s], as movant[s] to conclusively establish the absence or nonexistence of any defense. . . .' [Cit.]" Scott v. Aetna Finance Co., 201 Ga. App. 81, 82 ( 410 S.E.2d 203) (1991). "`The defendant's answer raised [other] issuable defense[s] which the proof offered by the plaintiff[s] failed to effectively negate.' [Cit.