write to new line?

Sounds kinda simple but can’t seem to get it to work.

Currently my game is asking for a name, upon a button click, this name and their score are stored in an array. I want this array to be saved to a text file, which it is, but it only stores 1 game save if you can understand that.

So the original text is getting written over each time the score and name are saved.

Here is what I’m trying:

using UnityEngine;
using System;
using System.Collections;
using System.Collections.Generic;
using System.IO;
using UnityEngine.UI;
using UnityEngine.EventSystems;

public class GUI_Button : MonoBehaviour {

public PlayerMovement GUIScript;
public RandomSpawn GUIScript1;
private int count = RandomSpawn.count;
public string PlayerName = "Enter name";
public string fileName = "leaderboard.txt";
public string FinalName = "";
public string count1 = "";
public string newline = "

";

void OnGUI ()
{
	if (PlayerMovement.livess <= 0) 
	{
		GUI.Button (new Rect (400, 200, 300, 200), "Score:" + (count+10));
		PlayerName = GUI.TextField (new Rect (400, 400, 300, 100), PlayerName);
		CountToString ();
		if (GUI.Button (new Rect (400, 500, 200, 100), "Save Score"))
			FinalName = PlayerName;
			StoreInArray ();
	}
}
void CountToString ()
{
	count1 = count.ToString();
}
void StoreInArray ()
{
	string[] PlayerAndScore = {FinalName, count1};
	System.IO.File.WriteAllLines(@"C:\Users\Plum\Desktop\Pixel Ninjav3.3\Assets\leaderboard.txt", PlayerAndScore);
	System.IO.File.AppendAllText(@"C:\Users\Plum\Desktop\Pixel Ninjav3.3\Assets\leaderboard.txt", newline);

}

}

void StoreInArray(){

string[] PlayerAndScore = {FinalName, count1};
StreamWriter w = File.AppendText( /path to file/);
w.Write(PlayerAndScore);
w.Close();
}

Hope this helps