Under this theory of recovery, however, "the contractual duties under which the employer would be liable for the acts of the independent contractor cannot be enforced by one not a party to the contract." Kidd v. Dentsply Intl. , 278 Ga. App. 346, 350 (2), 629 S.E.2d 58 (2006) (citation and punctuation omitted). Neither Calvin nor Jerline was a party to the Professional Services Agreement.