Employees of the Montgomery Commission retain the right to: form, join, or assist an employee organization; bargain collectively through a representative that the employees have chosen; engage in other lawful concerted activities for the purpose of collective bargaining; or refrain from an activity covered under this subsection. When an employee has a grievance under a collective bargaining agreement, the employee may present the grievance to the Montgomery Commission but may do so only through the employee organization certified as the exclusive representative for the bargaining unit.