Something

using System;
using System.Linq;

namespace ConsoleApplication1
{
    class Dong
    {
        public char Key
        {
            get;
            set;
        }

        public int Count { get; set; }

        public Dong(char c, int k)
        {
            this.Key = c;
            this.Count = k;
        }
    }

    class Program
    {
        static void Main(string[] args)
        {
            
            var word = "qv7qc77qx777qs7777qg77777qbv7bqbckbqqbvkbqgkbqhskbqpckbqbqvm" +
                "cmhhgmjjbgmppyctbqbivaypga7bbhjbqbxmawhhbqawwqx777kbqbjhbvapkatkhca" +
                "aamwhmwhwhwhwhwhapkqmpkqc7bhbhwgawiiqwiqbv";
            var chars = word.GroupBy(w => w).Where(g => g.Count() > 2).Select(g => new Dong( g.Key,g.Count() ));

            foreach (Dong d in chars)
            {
                Console.WriteLine(d.Key + ": " + d.Count);
            }
            Console.ReadKey();

        }
    }
}