ASP.NET Bootstrap breaking Formulars on mobile devices

Question

I developed a site with ASP.NET and bootstrap the layout is ok for applications with screen up to the size of ipad. However in the ipad mini I would like that occurs a line break where the Lstlojas stay above the rest of the form currently both are in the same line and so if on poem.

<div class="row-fluid">
  <div class="col-xs-4">
    <asp:ListBox ID="LstLojas" runat="server" height="156px" AutoPostBack="True"></asp:ListBox>
  </div>
</div>

<div class="row-fluid">
  <div class="col-xs-8">
    <div class="from-group">
      <asp:TextBox ID="txtLocal" runat="server" placeholder="Local" class="col-xs-10"></asp:TextBox>
      <asp:TextBox ID="txtLocalID" runat="server" placeholder="ID" class="col-xs-2 text-muted"></asp:TextBox>


      <asp:TextBox ID="txtEndereco" runat="server" placeholder="Endereço" class="col-xs-8"></asp:TextBox>
      <asp:TextBox ID="txtComplemento" runat="server" placeholder="Complemento" class="col-xs-4"></asp:TextBox>


      <asp:TextBox ID="txtBairro" runat="server" placeholder="Bairro" class="col-xs-4"></asp:TextBox>
      <asp:TextBox ID="txtCidade" runat="server" placeholder="Cidade" class="col-xs-4"></asp:TextBox>
      <asp:TextBox ID="txtUf" runat="server" placeholder="Uf" class="col-xs-2"></asp:TextBox>
      <asp:TextBox ID="txtCep" runat="server" placeholder="CEP" class="col-xs-2"></asp:TextBox>


      <asp:TextBox ID="txtContato1" runat="server" placeholder="Contato 1" class="col-xs-8"></asp:TextBox>
      <asp:TextBox ID="txtDDD1" runat="server" placeholder="DDD" class="col-xs-2"></asp:TextBox>
      <asp:TextBox ID="txtTelefone1" runat="server" placeholder="Telefone" class="col-xs-2"></asp:TextBox>


      <asp:TextBox ID="txtContato2" runat="server" placeholder="Contato 2" class="col-xs-8"></asp:TextBox>
      <asp:TextBox ID="txtDDD2" runat="server" placeholder="DDD" class="col-xs-2"></asp:TextBox>
      <asp:TextBox ID="txtTelefone2" runat="server" placeholder="Telefone" class="col-xs-2"></asp:TextBox>


      <asp:TextBox ID="txtEmail1" runat="server" placeholder="Email 1" class="col-xs-6"></asp:TextBox>
      <asp:TextBox ID="txtEmail2" runat="server" placeholder="Email 2" class="col-xs-6"></asp:TextBox>


      <asp:Label ID="lblAtualizacao" runat="server" Text="Ultima altualização: "></asp:Label>
      <br />
      <asp:Label ID="lblStatusSuccess" runat="server" Text="" class="text-success"></asp:Label>
      <asp:Label ID="lblStatusError" runat="server" Text="" class="text-danger"></asp:Label>
    </div>
  </div>
</div>

<div class="row-fluid">
  <div class="col-xs-4"></div>
  <div class="col-xs-4">
    <br />
    <br />
    <asp:Button id="Button1" runat="server" cssClass="btn btn-warning" Text="Salvar" />
    <asp:Button id="Button2" runat="server" cssClass="btn btn-danger" Text="Excluir" />
  </div>
</div>