A member who establishes service credit under §25.71 of this title (relating to Service Credit for Eligible Active Military Duty under the Uniformed Services Employment and Re-Employment Rights Act) cannot use the same military service to establish military service credit under §25.61 of this title (relating to Service Credit for Eligible Military Duty). No additional service credit may be given for any school years of military duty eligible for service credit already granted for service in the public schools of Texas.