gsm sim900a not responding to at commands

Hey guys, I have an issue here, I bought a new A6 GSM module a week ago, but when started testing it using Arduino Mega, I couldn’t get the response from the module, even if I send AT commands it does nothing. here is my code:
#include <SoftwareSerial.h>

//Create software serial object to communicate with A6
SoftwareSerial mySerial(3, 2); //A6 Tx & Rx is connected to Arduino #3 & #2

void setup()
{
//Begin serial communication with Arduino and Arduino IDE (Serial Monitor)
Serial.begin(9600);

//Begin serial communication with Arduino and A6
mySerial.begin(9600);

Serial.println(“Initializing…”);
delay(1000);

mySerial.println(“AT”); //Once the handshake test is successful, it will back to OK
updateSerial();
mySerial.println(“AT+CSQ”); //Signal quality test, value range is 0-31 , 31 is the best
updateSerial();
mySerial.println(“AT+CCID”); //Read SIM information to confirm whether the SIM is plugged
updateSerial();
mySerial.println(“AT+CREG?”); //Check whether it has registered in the network
updateSerial();
mySerial.println(“AT+COPS?”); // check which network you are connected to
updateSerial();
mySerial.println(“AT+COPS=?”); // return the list of operators present in the network

updateSerial();
}

void loop()
{
updateSerial();
}

void updateSerial()
{
delay(500);
while (Serial.available())
{
mySerial.write(Serial.read());//Forward what Serial received to Software Serial Port
}
while(mySerial.available())
{
Serial.write(mySerial.read());//Forward what Software Serial received to Serial Port
}
}

Please I need your help guys.