SIM800L send text and make call use %55 of memory.

Sketch uses 6,568 bytes (20%) of program storage space. Maximum is 32,256 bytes.
Global variables use 1,142 bytes (55%) of dynamic memory, leaving 906 bytes for local variables. Maximum is 2,048 bytes.
Is there any different library to reduce memory. 55% is too much. I want to use this module with SDcard, RTC and i don’t have space.

#include <GPRS_Shield_Arduino.h>
#include <SoftwareSerial.h>
#include <Wire.h>

#define PIN_TX 7
#define PIN_RX 8
#define BAUDRATE 9600
#define PHONE_NUMBER “00306985952400”

GPRS gprsTest(PIN_TX,PIN_RX,BAUDRATE);//RX,TX,PWR,BaudRate

void setup() {
Serial.begin(9600);
while(!gprsTest.init()) { //gprs init, this use 25% of dynamic memory
delay(1000);
Serial.print(F(“init error\r\n”));
}
Serial.println(F(“gprs init success”));
Serial.println(“start to send message …”);
gprsTest.sendSMS(PHONE_NUMBER,MESSAGE); //define phone number and text
Serial.println(F(“start to call …”));
gprsTest.callUp(PHONE_NUMBER);
}

void loop() {
//nothing to do
}