Save and Retrieve Score not working!

Dear all,
I have been encountering a very irritating problem when creating my first app. I am trying to use the playerpref to save my score, but when it restarts, the highscore is reset to 0. I am an absolute beginner, so please treat me like a dunce. Ill paste the 2 scripts I have for scoring a point on trigger, and the other is the general score system.
I have tried this on my phone, and whenever I score a point and update the score, the highscore is 0.
Many thanks for the help :slight_smile:
from fatmanspineapple
For the score point
using UnityEngine;
using System.Collections;

public class ScorePoint : MonoBehaviour {

	void OnTriggerEnter2D(Collider2D collider){
		if(collider.tag == "Player"){
			ScoreSystem.AddPoint();
			gameObject.SetActive(false);
		}


}
	}

For the score system

using UnityEngine;
using System.Collections;

public class ScoreSystem : MonoBehaviour {

	static int score = 0;
	static int highScore = 0;
	static ScoreSystem instance;

	static public void AddPoint(){
				score++;

				if (score > highScore) {
						highScore = score;
				}
		}


	void Start() {
		PlayerPrefs.GetInt("highScore", 0);


	}
	void OnDestroy(){
		PlayerPrefs.SetInt ("highScore", highScore);
		score = 0;

		  }
		                 
	void Update () {
		guiText.text = "S:" + score +  "

HS:" + highScore;

	}
}

you never initialize highScore from player prefs - line 20:

PlayerPrefs.GetInt("highScore", 0);

should be

highScore = PlayerPrefs.GetInt("highScore", 0);