Не записывает новые данные в файл телефонный справочник

#include <iostream>
#include <iomanip>
#include <fstream>
#include <string>
using namespace std;
 
struct Contact {
string name, number, notes;
};
Contact contactList[100];
 
int rec_num = 0;
int num_entries;
 
string toUpper (string S) {
for (int i= 0; i<S.length(); i++)
S[i] = toupper(S[i]);
return S;
}
 
void ReadFile () {
string S;
fstream input("PhoneData.txt");
while (!input.eof() && !input.fail()){
input >> contactList[rec_num].name
>> contactList[rec_num].number;
getline(input, S);
contactList[rec_num].notes = S;
rec_num++;
}
cout << "Book read." << endl;
num_entries = rec_num;
input.close();
return;
}
void StoreFile () {
fstream F("PhoneDat.txt");
rec_num = 0;
 
while (rec_num < num_entries){
F << contactList[rec_num].name << " "
<< contactList[rec_num].number << " "
<< contactList[rec_num].notes << " " << endl;
rec_num++;
}
cout << "Phonebook stored." << endl;
return;
}
 
void add_name(string name, string number, string notes){
contactList[num_entries].name = name;
contactList[num_entries].number = number;
contactList[num_entries].notes = notes;
num_entries++;
return;
}
void retrieve_name(string name){
for (int i = 0; i < num_entries; i++){
if (toUpper(contactList[i].name) == toUpper(name)) {
cout << "Phone Number: " << contactList[i].number << endl
<< "Notes: " << contactList[i].notes << endl;
return;
}
}
cout << "Name not found" << endl;
return;
}
 
void sortList() {
int i;
Contact temp;
 
for(int j=0; j < num_entries; j++) {
for(i = j+1; i < num_entries; i++) {
if(contactList[j].name.compare(contactList[i].name) > 0) {
//Swap the entries if their names are not in ascending order
temp = contactList[j];
contactList[j] = contactList[i];
contactList[i] = temp;
}
}
}
cout << "Sorted the list. Press l to list all the contacts";
}
 
void listAllContacts() {
int i = 0;
while (i < num_entries) {
cout << "-- " << contactList[i].name << " "
<< contactList[i].number << endl
<< "-- " << contactList[i].notes << endl << endl;
i++;
}
}
 
int main(){
string name, number, notes;
string FileName;
char command;
 
FileName = "PhoneData.txt";
ReadFile ();
cout << "Use \"e\" for enter, \"f\" for find, \"q\" to quit."
<< endl << "Command: ";
cin >> command;
while (command != 'q'){
switch (command){
case 'e': cin >> name; cout << "Enter Number: ";
cin >> number; cout << "Enter Notes: ";
cin.ignore(); getline(cin, notes);
add_name(name, number, notes); break;
case 'f': cin >> name; retrieve_name(name); break;
case 's': sortList(); break;
case 'l': listAllContacts(); break;
}
cout << "\nCommand: "; cin >> command;
}
StoreFile();
cout << "All set !";
return 0;
}