旋转横幅上显示的金额随每页重新加载而变化

We are facing a very weird problem and i have tried looking for a solution but found none. We built a site in core php and it has a rotating banner/ slider that displays an amount that changes when a user purchases something on the site.

For example, the site sale is $1000 and every time a user makes a purchase that figure on the banner changes from $1000 to may be $1050 and so on.

Now the problem that is being faced is that sometimes (not all the times) when we do a page refresh, the amount on the banner increments by a specific amount say $25. So if you refresh the page 4 times, the amount would increase by $100.

Could someone please please suggest what could be wrong here?

Sorry for not adding the code earlier.

This code is in codeigniter

Controller file say home.php code

$count_Values  = $this->home_model->countHome();//check if there any
update in order table ie if any purchase made or not

$count_Values1  =$this->home_model->getTotalDonation();//get total
doantion amount from db
$updateDonation =$this->home_model->updateDonationDetails($count_Values);//update
amount on db
$data['count']    = number_format($count_Values1,0);//for view

Model file say home_model.php

/*
@Function name:countHome
@Purpose      :Used to count donation in order table
*/
public function countHome()
{
   $this->db->select('modify_date');
   $this->db->from('tbl_common');
   $this->db->where('id',1);
   $query1=$this->db->get();
   $result=$query1->row();
   $date  =$result->modify_date;
   $query=$this->db->query("select sum(pac_donation_to_owner) as totalpac
from tbl_order where order_status='1' and order_createddate >
'$date'");
  $total = $query->row()->totalpac;
  return  ($total);
}

    /*
    @Function name:getTotalDonation
    @Purpose      :get total donation
    */
    public function getTotalDonation()
    {
         $this->db->select('value');
         $this->db->from('tbl_common');
         $this->db->where('id',1);
         $query=$this->db->get();
         $result=$query->row();
         return $result->value;
    }
    /*
    @Function name:updateDonationDetails
    @Purpose:for update total donation in tbl_common
    */
    public function updateDonationDetails($values)
    {
        $this->db->select('value');
        $this->db->from('tbl_common');
        $this->db->where('id',1);
        $query  =$this->db->get();
        $result =$query->row();
        $updateValue    = $result->value;
        $data['modify_date']  = date('Y-m-d h:i:s');
        $data['value']  =$values+$updateValue;
        $this->db->where('id',1);
        $this->db->update('tbl_common', $data);

    }

View.php file
  <?php echo $count; ?>

Thanks