Unity2D onTriggerExit2D not working!! Help!!

Hey guys,

So basically I am creating a 2D platformer with Unity and I have run into a problem.

I am trying to create a boundary box around my map, so that when enemies inside hit the edges of the map, they switch direction.

I am quite sure that the code i have written is good but can someone please check it out for me? It is driving me crazy as it should be working!!

 using UnityEngine;
 using System.Collections;
 
 public class Boundaries : MonoBehaviour 
 {    
     private GameObject Enemies;
 
     // Use this for initialization
     void Start () 
     {
         Enemies = GameObject.FindGameObjectWithTag("Enemy");
     }
     
     // Update is called once per frame
     void Update () 
     {
 
     }
 
     void onTriggerExit2D(Collider2D other)
     {
         Debug.Log ("Left The Building");
 
         if (other.gameObject.tag == "Enemy")
         {
             Debug.Log ("Left The Building");
             other.gameObject.transform.rotation = Quaternion.Euler (transform.rotation.x, 180, transform.rotation.z);
             //Enemies.gameObject.transform.rotation = Quaternion.Euler (transform.rotation.x, 180, transform.rotation.z);
         }
 
     }
 }

Just to let you know the boxCollider2D around the map has been set to trigger, and the enemies have two box collider2D's, one is a trigger and one isn't.

Not even the debug.log's are working !! :S

Thanks :)