为什么我的代码跳过了这个循环

我为我的noob问题提前道歉。我第一次接触编程是在我目前的课程中。关于这个问题，

为什么我的代码跳过第二个while循环。当我选择p或p作为输入时，我仍然会被要求输入与第一个while循环有关的信息，而不是第二个。例如分钟数，而不是白天的分钟数/晚上的分钟数。

 #include <iostream>
    #include <iomanip>
    using namespace std;
    int main()
    {
        char service;
        int number;
        int minutes;
        int dayMinutes;
        int nightMinutes;
        double bill;
        double const REG_FEE = 10.00;
        double const PREM_FEE = 25.00;
        double const REG_MIN = 0.20;
        double const PREM_DAY = 0.10;
        double const PREM_NIGHT = 0.05;
        cout << "Please enter your account number: ";
        cin >> number;
        cout << "Please enter your service type (regular or premium): ";
        cin >> service;
        while (service == 'r' || 'R')
    {
            cout << "How many minutes have been used for this service?: ";
            cin >> minutes;
            if (minutes < 50)
            {
                bill = REG_FEE;
                cout << fixed << showpoint << setprecision(2);
                cout << "The account number entered was: " << number << "." << endl;
                cout << "The service type entered was: " << service << "." << endl;
                cout << "You used: " << minutes << " minutes." << endl;
                cout << "Your bill is $" << bill << "." << endl;
            }
            else
            {
                bill = ((minutes - 50) * REG_MIN) + REG_FEE;
                cout << fixed << showpoint << setprecision(2);
                cout << "The account number entered was: " << number << "." << endl;
                cout << "The service type entered was: " << service << "." << endl;
                cout << "You used: " << minutes << " minutes." << endl;
                cout << "Your bill is $" << bill << "." << endl;
            }
        return 0;
    }
        while (service == 'p' || 'P')
    {
            cout << "How many minutes were used during the day?: ";
            cin >> dayMinutes;
            cout << "How many minutes were used during the night?: ";
            cin >> nightMinutes;
            if (dayMinutes > 75)
            {
                bill = ((dayMinutes - 75) * PREM_DAY) + PREM_FEE;
            }
            if (nightMinutes > 100)
            {
                bill = ((nightMinutes - 100) * PREM_NIGHT) + PREM_FEE;
                bill = bill + PREM_FEE;
                cout << fixed << showpoint << setprecision(2);
                cout << "The account number entered was: " << number << "." << endl;
                cout << "The service type entered was: " << service << "." << endl;
                cout << "You used: " << dayMinutes + nightMinutes << " minutes." << endl;
                cout << "Your bill is $" << bill << "." << endl;
            }
            else
            {
                cout << "You have entered an invalid service code.";
            }
        return 0;
    }
        return 0;
    }