Save changes into SD

Using Arduino Storage
8

Hi guys thanks for your help.

Right now i made a smaller program just to learn how to use SD properly. I have a txt file in the Sd (user.txt) with 4 users codes. For now i im trying to save it like: user[1]=67202....user[4]61014 but ir doesn't work. The serial shows user[1]=59, user[2]=59, user[3]=59,user[4]=59. Here is my code.

67202
62601
60920
61014

#include <String.h>
#include <SD.h>

int CS=53;
String dataString;
File dataFile;

int i=1;

unsigned long dato;
unsigned long user[100];

void setup(){
  Serial.begin(115200);
  Serial.println("Initiating SD");
  pinMode(CS, OUTPUT);
  if(!SD.begin(CS)){
    Serial.println("SD failed");
    return;
  }
  Serial.println("SD OK");
  leerSD();
}
  
void leerSD(){
  Serial.println("Reading SD...");
  dato=0;
  dataFile=SD.open("user.txt",FILE_READ);
    // read from the file until there's nothing else in it:
    while (dataFile.available()&& dataFile.peek() != '\n'){
      Serial.write(dataFile.read()); 
      delay(50);
    }
      asignauser();
 }

void asignauser(){
        if(i<=4){
        user[i]=dataFile.read();
        Serial.print("The user");
        Serial.print(i);
        Serial.print("is:");
        Serial.println(user[i]);
        i++;
        leerSD();
        }
        loop();
}

void loop(){
}

Many thanks!!