So the law says that you are not required to be a part of the Union but the Union is required to represent you? That doesn't sound fair. If you don't want to be part of the Union then you shouldn't have to join. But if the Union negotiates a pay raise for their members then you shouldn't be covered by it.
The statute doesn’t require that the union represent anyone who is not a member. The statute merely provides that union membership shall be made a condition of employment.