How do I convert a 12-bit cell phone number to a 6-byte array BCD code?

Converts a 12-bit cell phone number (11 digits before 0, such as 013482339442), converting 12 to 8421 yards, and then combining them into 6 byte arrays, tentatively named BCD6, the conversion method is as follows:

Using System;
Using System.Collections.Generic;
Using System.Linq;
Using System.Text;

Namespace Consoledemo
{public
    class BCD6
    {public
        string Getmobileno (byte[] mobilearray)
        {
            StringBuilder sb = new StringBuilder ();
            for (int i = 0; i < 6; i++)
            { 
                byte bb=mobilearray[i];
                Sb. Append (((Byte) (BB >> 4)). ToString ());
                Sb. Append ((Byte) ((Byte) (BB << 4) >> 4). ToString ());
            }
            Return SB. ToString ();
        }

        Public byte[] ConvertToBCD6 (string mobileno)
        { 
            byte[] mobilearray=new byte[6];
            if (mobileno.length!=) return mobilearray;
            for (int i = 0; i < 6; i++)
            {
                Mobilearray[i] = Convert.tobyte (Mobileno.substring (i*2, 2);
            }
            return mobilearray;
        }
    }

Console test Code:

Using System;
Using System.Collections.Generic;
Using System.Linq;
Using System.Text;

Namespace Consoledemo
{
    class program
    {
        static void Main (string[] args)
        {

            byte[] Mobilearray = new Byte[6] {0x01, 0x34, 0x82, 0x33, 0x94, 0x42};
            BCD6 bcd6 = new BCD6 ();
            Console.WriteLine (Bcd6. Getmobileno (Mobilearray));

            byte[] Mobile2 = bcd6. ConvertToBCD6 ("013482339442");
            Console.WriteLine (Bcd6. Getmobileno (Mobile2));

            Console.read ();}}