Resignation acceptance / relieving letter

All professional I am a Sr HR Professional in one of the manufacturing and trading company based in South Delhi. One of my employee resigns after two and a half years of service, without serving notice period. He has handed over the company property to his immediate manager and given resignation letter in writing as well. As per our company policy, if person doesn't serve the notice period, we deduct the notice period amount from his full and final settlement as per the terms of his appointment. Now, I would like to know that isn't it mandatory that when someone resigns from the company, employer has to give some sort of communication to the employee mentioning his service tenure, designation and his last working day?? Employer is saying that its their WISH to issue a communication or not which is not understood by me at all. As per the Industrial Employment (standing order) act 1946, wherein it has been clearly mentioned that employer has to issue service certificate to an workmen with tenure and employment details. My question is, what is the definition of 'workmen' in this Act? Isn't Workmen refers to Employees as well?? Please do help in providing correct answer to this problem.