Unreadable files after writing?

I am using a mega to get data from sensors and trying to write to a SD card, so the wiring is
SS 10 53
MOSI 11 51
MISO 12 50
SCK 13 52
The module I used is SUNFOUNDER SD card module
Amazon:https://www.amazon.com/SunFounder-Module-Socket-Reader-Arduino/dp/B01G8BQV7A
Here is my code:

/*
Writing Sensor Data to an SD card
//
This example shows how to write data
to an SD card using the SD library.
//
The circuit:

  • SD card attached to SPI bus as follows:
    ** MOSI - pin 11
    ** MISO - pin 12
    ** CLK - pin 13
    ** CS - pin 10 Uno (53 on Mega)
    SPI Uno Mega
    SS 10 53
    MOSI 11 51
    MISO 12 50
    SCK 13 52

*/
//
#include <SD.h>
#include <SPI.h>
//
//the hardware CS pin (10 on most Arduino boards,
// 53 on the Mega) must be left as an output or the SD
// library functions will not work.
const int CSpin = 53;
String dataString =""; // holds the data to be written to the SD card
float sensorReading1 = 1.00; // value read from your first sensor
float sensorReading2 = 2.00; // value read from your second sensor
float sensorReading3 = 3.00; // value read from your third sensor
File sensorData;
//
//
void setup()
{
// Open serial communications
Serial.begin(9600);
Serial.print(“Initializing SD card…”);
pinMode(CSpin, OUTPUT);
//
// see if the card is present and can be initialized:
if (!SD.begin(CSpin)) {
Serial.println(“Card failed, or not present”);
// don’t do anything more:
return;
}
Serial.println(“card initialized.”);
}
//
void loop(){
// build the data string
dataString = String(sensorReading1) + “,” + String(sensorReading2) + “,” + String(sensorReading3); // convert to CSV
saveData(); // save to SD card
delay(6000); // delay before next write to SD Card, adjust as required
}
//
void saveData(){
sensorData = SD.open(“data.csv”, FILE_WRITE);
if (sensorData){
sensorData.println(dataString);
sensorData.close(); // close the file
}
}

The setup function is ok, after I plug in the SD card, it displays “card initialized.” and started to write to files. But after I unplug the SD card and plug it into my PC to check the data, it was full of unreadable files, and I couldn’t even open it.
Any ideas?

so the wiring is
SS 10 53
MOSI 11 51
MISO 12 50
SCK 13 52

Which ONE pin did you actually connect the wire to? The SD card module doesn't have 10 pins, let alone 53, so none of those numbers refer to pins on the SD card module.

it was full of unreadable files, and I couldn't even open it.

The door to the room with no windows was locked, but I know that the room was a real mess inside. Give us a clue HOW you know the card was full of unreadable files, if you couldn't even open the SD card.