unable to display values from array in a view

Hi all,

I am trying to out values using loop from an array, but facing error:

Message: Undefined index: payment_description

here my model:

PHP Code:

public function get_fee_invoice_4class($data){


    $this->anotherDb
    ->where('class_id',$data['id'])
    ->where('activated',1)
    ->where('role','Student');
    $student_query = $this->anotherDb->get('users');
    
    $totalrows = $student_query->num_rows(); 




    for($i=0;$i<$totalrows;$i++) {
                                  
            $result = $student_query->result_array();
            $student_id = $result[$i]['id'];

        $this->anotherDb
        ->where('payment_student', $result[$i]['id'])
        ->where('date_format(fee_month,"%d-%m%Y") >=date_format(curdate(),"00-%m-%Y")')
        ->where('payment_status=0');
        $this->anotherDb
        ->select('payment_amount', 'payment_description','payment_student');
        $query = $this->anotherDb->get('payments');
                
        $result_array[] = $query->result_array();

        }
    return $result_array;      
    } 


Here my controller:

PHP Code:

 public function rep_fee_invoice_4class() 
    {

        $data = array(  
                    //'fee_type'    => $this->input->post('fee_type'),
                    'id'     => $this->input->post('class')
                    );
 
        $this->data['fee_detail']= $this->Fee_model->get_fee_invoice_4class($data);
/*       
        echo '<pre>';
        print_r($this->data['fee_detail']);
        echo '</pre>';
        die(); 
*/
        $template_pdf = $this->load->view('reports/rep_fee_invoice_4class_html', $this->data, TRUE);

        $html2pdf = new Html2Pdf();
        $html2pdf->writeHTML($template_pdf);
        $html2pdf->output('Student_Fee_invoice.pdf', 'D');
    }     


Here my view, I am using html2pdf for pdf outpu.

PHP Code:

<style type="text/Css">
<!--.test1
{
    border: solid 1px #FF0000;
    background: #FFFFFF;
    border-collapse: collapse;
}
-->
</style>
<page style="font-size: 14px;">

<div style="fload: left; width: 48%;">
    <span style="font-weight: bold; font-size: 18pt; color: #FF0000; font-family: Times">
    <h1 style="font-size: 24px; text-align: center;">
    Fee Invoice</h1>
    <br></span>
<?php
    $school_name = ($this->Main_model->get_settings('school_name'));
    $school_address = ($this->Main_model->get_settings('address'));
    $phone_no = ($this->Main_model->get_settings('phone_no'));
?>
    <br>
    <p> School Name: <?php echo $school_name; ?></p>
    <p> School Address: <?php echo $school_address; ?></p>
    <p> Phone No: <?php echo $phone_no; ?></p>    
    <table style=" border: 1px solid #555555;">
        <thead>
                <tr>
                    <th style=" border: 1px solid #555555;">No.</th>
                    <th style=" border: 1px solid #555555;">Particulars</th>
                    <th style=" border: 1px solid #555555;">Amount</th>
                </tr>
        </thead>
        <tbody>
              <?php
                if(isset($fee_detail) && is_array($fee_detail) && count($fee_detail)): $i=1;
                foreach ($fee_detail as $key => $data) { 
                ?>
                <tr>
                    <td style=" border: 1px solid #555555;"><?php echo $i; ?></td>
                    <td style=" border: 1px solid #555555;"><?php echo $data['payment_description']; ?></td>
                    <td style=" border: 1px solid #555555;"><?php echo $data['payment_amount']; ?></td>

                </tr>
                <?php
                    $i++;
                      }
                    else:
                ?>
                <tr>
                    <td style=" border: solid 1px #000000 colspan="8" >No Records Found..</td>
                </tr>
                <?php
                    endif;
                ?>
        </tbody>
                      <!--<td style="width: 100%">Test 1</td> </tr>-->
    </table><br />
    </div>
    </page> 


I tried 

/*      
       echo '<pre>';
       print_r($this->data['fee_detail']);
       echo '</pre>';
       die();
*/
and it return the following but unable to display these fields in view.

Array
(
   [0] => Array
       (
           [0] => Array
               (
                   [payment_amount] => 1800
               )

       )

   [1] => Array
       (
           [0] => Array
               (
                   [payment_amount] => 1800
               )

           [1] => Array
               (
                   [payment_amount] => 1800
               )

           [2] => Array
               (
                   [payment_amount] => 1800
               )

           [3] => Array
               (
                   [payment_amount] => 1800
               )

           [4] => Array
               (
                   [payment_amount] => 1800
               )

           [5] => Array
               (
                   [payment_amount] => 1800
               )

           [6] => Array
               (
                   [payment_amount] => 1800
               )

           [7] => Array
               (
                   [payment_amount] => 1800
               )

           [8] => Array
               (
                   [payment_amount] => 1800
               )

       )

   [2] => Array
       (
           [0] => Array
               (
                   [payment_amount] => 1800
               )

           [1] => Array
               (
                   [payment_amount] => 1800
               )

           [2] => Array
               (
                   [payment_amount] => 1800
               )

           [3] => Array
               (
                   [payment_amount] => 1800
               )

           [4] => Array
               (
                   [payment_amount] => 1800
               )

           [5] => Array
               (
                   [payment_amount] => 1800
               )

           [6] => Array
               (
                   [payment_amount] => 1800
               )

           [7] => Array
               (
                   [payment_amount] => 1800
               )

       )

)