bool repeat= true;
bool flag = true;
            while (flag)
            {
                ConsoleKeyInfo ck = Console.ReadKey();
                switch (ck.Key)
                {
                    case ConsoleKey.DownArrow:
                        Console.CursorVisible = false;
                        Console.Clear();
                        ////////////// ТУТ ТВОЙ КОД
                        repeat = true;
                        break;
                    case ConsoleKey.UpArrow:
                        Console.CursorVisible = false;
                        Console.Clear();
                        ////////////// ТУТ ТВОЙ КОД
                        repeat = false;
                        break;

                    case ConsoleKey.Enter:
                        if (repeat)
                        { flag = false; }
                        else
                        {
                            Console.Clear();
                            goto start;
                        }
                        break;
                }