helping mpgh noob

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace helpin_mpgh_noob
{
    class Program
    {
        //
        // Next time learn to do your homework yourself.
        //

        const double UNIT_COST_FIRST_200 = 21.8;
        const double UNIT_COST_ABOVE_200 = 25.8;

        static void Main(string[] args)
        {
            //Ignore this, just a basic exception handler.
            AppDomain.CurrentDomain.UnhandledException += delegate(object sender, UnhandledExceptionEventArgs e)
            {
                Console.ForegroundColor = ConsoleColor.Red;
                Console.WriteLine(e.ExceptionObject.ToString());
                Console.ResetColor();
                Console.WriteLine("Press any key to exit");
                Console.ReadKey();
                return;
            };

            int accountId;
            double currentMeterReading;
            double previousMeterReading;
            Receipt receipt;
            int processCount = 0;

            while ((processCount == 0 || Console.ReadLine() == "y"))
            {
                Console.WriteLine("Enter account id");
                while (!int.TryParse(Console.ReadLine(), out accountId))
                    Console.WriteLine("Enter account id again, failed to cast input to integer.");

                Console.WriteLine("Enter current meter reading");
                while (!double.TryParse(Console.ReadLine(), out currentMeterReading))
                    Console.WriteLine("Enter meter reading again, failed to cast input to double.");

                Console.WriteLine("Enter previous meter reading");
                while (!double.TryParse(Console.ReadLine(), out previousMeterReading))
                    Console.WriteLine("Enter previous meter reading again, failed to cast input to double.");

                receipt = Process(accountId, currentMeterReading, previousMeterReading);

                //Print results
                Console.WriteLine("===================<Receipt for {0}>===================", receipt.accountId.ToString());
                Console.WriteLine("Account ID: {0}", receipt.accountId.ToString());
                Console.WriteLine("Current meter reading: {0}", receipt.currentMeterReading.ToString());
                Console.WriteLine("Previous meter reading: {0}", receipt.previousMeterReading.ToString());
                Console.WriteLine("Amount consumed: {0}", receipt.ammountUsed.ToString());
                Console.WriteLine("Amount to be paid: {0}", receipt.overallPrice.ToString());
                Console.Write("\n\n\n");


                Console.WriteLine("Do you want to process another? type \"y\" to enter another");
                processCount++;
            }
        }

        private struct Receipt
        {
            public int accountId;
            public double currentMeterReading;
            public double previousMeterReading;
            public double ammountUsed;
            public double overallPrice;
        }

        private static Receipt Process(int accountId, double currentMeterReading, double previousMeterReading)
        {
            Receipt receipt = default(Receipt);

            receipt.currentMeterReading = currentMeterReading;
            receipt.previousMeterReading = previousMeterReading;
            receipt.accountId = accountId;

            receipt.ammountUsed = receipt.currentMeterReading - receipt.previousMeterReading;

            double leftOver = receipt.ammountUsed - 200;
            if (leftOver > 0)
                receipt.overallPrice = ConvertSenToRinggit(200 * UNIT_COST_FIRST_200) + ConvertSenToRinggit(leftOver * UNIT_COST_ABOVE_200);
            else
                receipt.overallPrice = ConvertSenToRinggit(receipt.ammountUsed * UNIT_COST_FIRST_200);

            return receipt;
        }

        private static double ConvertSenToRinggit(double sen)
        {
            return sen / 100;
        }
    }
}