While i get from HTTP server using Sim800l with MEGA (Initailly Loss of 54kb data and each per line )

[ashwin21]

Hi everyone! I'm ashwin

I try to get 54KB of data using sim800l(Retrive from HTTP Server) with mega and stored to SD.Actually i got the data both softwareserial and hardwareserial but initially i got big loss of data and after i also get loss in each line per single byte data loss
i didn't know why i get this using this code
Using Serial baudrate is 9600 for both serial and myserial

if(myserial.available()){
   while(true){
      c = myserial.read();
      Serial.print(c);
      // save file byte
      if (c == '}'){
         break; 
      }
   }
}

Acutal data;
actualdata.txt (54.0 KB)
while i get data;
char gsmdata.txt (48.9 KB)

here you all can see the loss of data.

Meanwhile i try to storing the char gsmdata to SD card i facing here lots of '?' marks using the code

void(){
   myFile = SD.open("54kbdata.txt", FILE_WRITE);
   if (myFile) 
   {
    Serial.println("Writing to 54kbdata.txt...");
    if(myserial.available()){
       while(true){
        c = myserial.read();
        myFile.print(c);
        if (c == '}'){
           break;  
         }
       }
     }
    myFile.close();
    Serial.println("done.");
    } 
   else 
     {
       Serial.println("error opening 54kbdata.txt");
     }

actuall data is above the code

here you all can see the difference actual data and sd file size .

question data;
chargsmdatawithsd.txt (98.6 KB)

Im stuck here please help me.

Thanks Advance everyone!