Raycast hitting more than once

I’ve just noticed now that my raycast is behaving strangely, when I click on an object I want my ray to get the information of that object and behave accordingly, as of now it seems to multiply that ray each time I click on my objects.

Screenshot when i first click an object:

and heres the second time I click an object:

It has now output as if i’ve hit the second object twice, and this goes up by one each time i’ve clicked on a new object. Does anyone know why this is?

Here is my code:

using UnityEngine;
using System.Collections;

public class selectObject : MonoBehaviour 
{

	public bool isSelected = false;

	public string ballColor = "";

	public GameObject selectedBall;

	// Use this for initialization
	void Start () {
	
	}
	
	// Update is called once per frame
	void Update () 
	{

		playNextLevel ();

		if (Input.GetMouseButtonDown (0))
		{
			RaycastHit hitInfo = new RaycastHit ();
			bool hit = Physics.Raycast (Camera.main.ScreenPointToRay(Input.mousePosition), out hitInfo);

			if (Input.GetMouseButtonDown (0) && hit) 
			{
				Debug.Log("Hit " + hitInfo.transform.gameObject.name);

				if (hitInfo.transform.gameObject.tag == "redBall")
				{
					isSelected = true;
					ballColor = "red";
					selectedBall = hitInfo.transform.gameObject;
				}

				else if(hitInfo.transform.gameObject.tag == "blueBall")
				{
					isSelected = true;
					ballColor = "blue";
					selectedBall = hitInfo.transform.gameObject;
				}
				else if(hitInfo.transform.gameObject.tag == "greenBall")
				{
					isSelected = true;
					ballColor = "green";
					selectedBall = hitInfo.transform.gameObject;
				}
				else if(hitInfo.transform.gameObject.tag == "yellowBall")
				{
					isSelected = true;
					ballColor = "yellow";
					selectedBall = hitInfo.transform.gameObject;
				}
             }
        }
    }
}

Just making an answer to have it accepted. Thanks to @robertu, i realised i had my script on each of my Instantiated object whereas i should have had it on my camera which only calls one reference to the script