This is just wrong

Public Shared Function ApplyPhoneNumberFormatting(ByVal phoneNumber As String) As String
        Dim cleanPhoneNumber As String
        Dim formattedPhoneNumber As New System.Text.StringBuilder
        Dim i As Integer

                If phoneNumber Is Nothing Then
                        Return String.Empty
                End If

        cleanPhoneNumber = StripNonNumericCharacters(phoneNumber)

        If cleanPhoneNumber.Length = 0 Then
            Return String.Empty
        Else

            For i = 0 To 12

                Select Case i
                    Case 0
                        formattedPhoneNumber.Append("(")
                    Case 1
                        formattedPhoneNumber.Append(cleanPhoneNumber.Chars(0))
                    Case 2
                        formattedPhoneNumber.Append(cleanPhoneNumber.Chars(1))
                    Case 3
                        formattedPhoneNumber.Append(cleanPhoneNumber.Chars(2))
                    Case 4
                        formattedPhoneNumber.Append(") ")
                    Case 5
                        formattedPhoneNumber.Append(cleanPhoneNumber.Chars(3))
                    Case 6
                        formattedPhoneNumber.Append(cleanPhoneNumber.Chars(4))
                    Case 7
                        formattedPhoneNumber.Append(cleanPhoneNumber.Chars(5))
                    Case 8
                        formattedPhoneNumber.Append("-")
                    Case 9
                        formattedPhoneNumber.Append(cleanPhoneNumber.Chars(6))
                    Case 10
                        formattedPhoneNumber.Append(cleanPhoneNumber.Chars(7))
                    Case 11
                        formattedPhoneNumber.Append(cleanPhoneNumber.Chars(8))
                    Case 12
                        formattedPhoneNumber.Append(cleanPhoneNumber.Chars(9))

                End Select

            Next

            Return formattedPhoneNumber.ToString

        End If

    End Function

more here.