Error "no implicit conversion of Symbol into Integer" with gem savon rails

I am using the gem savon to read a xml, brought the results correctly. When I show in my view all fields of xml it shows correctly, but when I want to show only one of these fields it of the error. "" I put down my code.

class Code < ActiveRecord::Base

        attr_accessor :strDataInicial, :strDataFinal

    def initialize(strDataInicial)
        @strDataInicial = strDataInicial
    end

    def data
        if response.success?
            return document(response)
        else
            raise "Error Message"
        end
    end

    private

    def document(response)
        data = response.to_hash[:ocupacao_por_segmento_response][:ocupacao_por_segmento_result][:ocupacao_por_segmento]
        if data
            data
        else
            nil
        end

    end

    def response
        client.call(
            :ocupacao_por_segmento,
            message: {
                strDataInicial: @strDataInicial,
                strDataFinal: "03/25/2015",
                blnConsideraReservasDayUse: true,
                strGrupo1: "S",
                strGrupo2: "S",
                exibeValoresContaAvulsa: true,
                strPool: "S",
                hotelId: "1"
            }
        )
    end

    def client
        Savon.client(
            wsdl: "http://ift.tt/1Ql5onK",
            endpoint: "http://ift.tt/1Ql5onK",
            ssl_verify_mode: :none
        )
    end

end

class CodesController < ApplicationController

        def index
        @code = Code.new(params[:strDataInicial])
        @code = @code.data
    end

end

<%= form_tag root_url, method: :get do %>
<p>
  <%= text_field_tag :strDataInicial, params[:strDataInicial] %>
  <%= text_field_tag :strDataFinal, params[:strDataFinal] %>
  <%= submit_tag "Enviar" %>
</p>
<% end %>

<% if @code %>
  <dl id ="zip_info">
    <dt>Diaria Media:</dt>
    <dd><%= @code[:diariamedia] %></dd>
  </dl>
<% end %>