PAYMENT_NOTIFICATION on Eway admin email

I use Eway as a payment method and it all works well apart from the notification email sent to me (admin).

In the subject heading of the email it says PAYMENT_NOTIFICATION

i think a language string is not working correctly here.

Thank you for the report.

Please change the line:
$mailer->setSubject(JText::sprintf('PAYMENT_NOTIFICATION','eWAY','Accepted'));

to:
$mailer->setSubject(JText::sprintf('PAYMENT_NOTIFICATION_FOR_ORDER','eWAY','Accepted',$order->order_number));

in the file plugins/hikashoppayment/eway.php and that should solve the problem.