How to load a scene level randomly without repeating

Hi, currently I am working for my school's project. The issue is I try to load the scene randomly. When I click on the "Button to the Next Level" in the current scene, it works but the scenes in the list keep repeating. What I want is when the scene has load at once, so the current scene will be removed from the list. I am expected that the scenes will be load randomly whenever I click on the "Button to the Next Level" without repeating the previous scene until the list of the scenes is empty. This is the coding that I have tried so far:

 using UnityEngine;
 using System.Collections;
 using System.Linq;
 using System.Collections.Generic;
 
 public class NextLevel : MonoBehaviour
 {
     public Transform tweenTarget;
     public Vector3 hover = new Vector3(1.1f, 1.1f, 1.1f);
     public Vector3 pressed = new Vector3(1.05f, 1.05f, 1.05f);
     public float duration = 0.2f;
     Vector3 mScale;
     bool mStarted = false;
     bool mHighlighted = false;
 
 
     ////max number of load scene is 10
     protected const int MAX = 10;
     private List<int> scenes = new List<int>();
     
     void Start()
     {
         if (!mStarted)
         {
             mStarted = true;
             if (tweenTarget == null) tweenTarget = transform;
             mScale = tweenTarget.localScale;
             
                // Initialize the list with levels
             scenes = new List<int>(Enumerable.Range(1,MAX));
         }
     }
     
     void OnEnable()
     { if (mStarted && mHighlighted) OnHover(UICamera.IsHighlighted(gameObject)); }
     
     void OnDisable ()
     {
         if (mStarted && tweenTarget != null)
         {
             TweenScale tc = tweenTarget.GetComponent<TweenScale>();
 
             if (tc != null)
             {
                 tc.scale = mScale;
                 tc.enabled = false;
             }
         }
     }
 
     void OnPress (bool isPressed)
     {
         if (enabled)
         {
             if (!mStarted) Start();
             TweenScale.Begin(tweenTarget.gameObject, duration, isPressed ? Vector3.Scale(mScale, pressed) :
                 (UICamera.IsHighlighted(gameObject) ? Vector3.Scale(mScale, hover) : mScale)).method = UITweener.Method.EaseInOut;
         }

             //No scenes left in the list, so exit
             if(scenes.Count == 0)
             {
                 Application.LoadLevel("QuitScene");
             }
 
             // Get a random index of the remaining scenes in the list
             int randomIndex = Random.Range(0, scenes.Count);
             int level = scenes[randomIndex];
             scenes.RemoveAt(randomIndex); // Removes the level from the list
             AutoFade.LoadLevel(level, 1,1,Color.black);
 
             isPressed = false;
     }
 
     void OnHover (bool isOver)
     {
         if (enabled)
         {
             if (!mStarted) Start();
             TweenScale.Begin(tweenTarget.gameObject, duration, isOver ? Vector3.Scale(mScale, hover) : mScale).method = UITweener.Method.EaseInOut;
             mHighlighted = isOver;
         }
     }
 }