from what I know, it is 28 days after 5 years of completion of service. I have seen people being paid as per this calculation. However, if there has been a change of rules lately, I am not aware of that.
In this case, I would suggest Sohail to go to NHRC and seek guidance before taking up the matter further with the company. This would clear things. I am confident NHRC will give the right picture.
Furthermore, if an employee is terminated due to misconduct, then it is a totally different story. Even in such an unwanted situation which is not common, an employee can always fight in the Labour Court to prove his innocence. It is not so easy for any employer to terminate an employee due to misconduct. Otherwise, unscrupulous employers and there are many of them around, would have used this tool to rob employees of their ESB.