$users = new User();
    $users->select('id');
    $users->where('ban_reason', NULL);
    $users->where('active', 1);
    $users->order_by('created', 'desc');
    $query = $users->get_raw();


    foreach($query->result() as $row) {
      $user = new User($row->id);
      if($user->last_fee()) {
        var_dump($row->id.': '.$user->last_fee());
        echo '<hr>';
      }
    }