Rewrite part of the example code from Adafruit FONA

[johnwasser]

So something like:

// call a phone!
    char number[] = "5558675309";
    Serial.print(F("Calling ")); 
    Serial.println(number);
    if (!fona.callPhone(number)) {
      Serial.println(F("Failed"));
    } else {
      Serial.println(F("Sent!"));
    }