Program Help. Flag controlled loop.

[MarkyMark]

I've been struggling with this and can't seem to figure it out. I'm supposed to use a flag controlled loop and as you can tell from reading the code I have no clue what I'm doing.

An Internet service provider has three different subscription
packages for its customers:

Package A: For $15 per month with 50 hours of access provided.
Additional hours are $2.00 per hour over 50 hours.
Assume usage is recorded in one-hour increments,

Package B: For $20 per month with 100 hours of access provided.
Additional hours are $1.50 per hour over 100 hours.

Package C: For $25 per month with 150 hours access is provided.
Additional hours are $1.00 per hour over 150 hours

Assume a 30-day billing cycle.

Write a program that calculates a customer’s monthly charges.
Use if/else construct for validation & Validate all input.
Show console dialog. It must be readable.

Demonstrate test cases as described in table:

Test Case Package Hours
1 A 50
2 a 51
3 B 100
4 b 101
5 C 149
6 c 151
7 C 721
8 d 720
*/

void main()
{
	cout << "Thank you for choosing Marky's Internet Service Provider!" << endl;
	cout << "Please enter a package choice(A,B, or C): " << endl;

	char package_choice(0);
	cin >> package_choice;

	if(package_choice == 'A' || package_choice == 'a')
	{
		cout << "You have selected package choice A!" << endl;
		cout << "Please input the amount of hours of usage: " << endl;

		bool flag = false;

		int usage_hrs(0);
		cin >> usage_hrs;
		if(usage_hrs <= 0 && usage_hrs >= 720)
			cout << "Invalid amount of hours." << endl;

		cout << "You have input " << usage_hrs << " hours." << endl;

		if(usage_hrs >= 0 && usage_hrs <= 50)
			usage_hrs = 15;
		cout << "Your monthly bill is: $" << usage_hrs << endl;

		while(!flag)
		{

[mutexe]

It seems that you need to set your flag to false when your hours value gets to:
1. 50 if package A
2. 100 if package B
OR
3. 150 if package C

this means when your flag == false, your while loop will stop and that'll be the end of your calculation.