This is in addition to what Mr. Atul Sharma has written. While an organization cannot put on hold the wages and travel expenses of any employee, what merits clarification is whether your exit from the company was smooth or if it had some negative connotation. Did the company force you to resign? Were you involved in any misconduct?
Forfeiture of wages is a legally accepted punishment; however, it has to be awarded if the misconduct is proved in conducting an inquiry. Nonetheless, organizations may resort to non-payment or partial payment without following this due process of law.
How many months/years did you serve in this company? How were your relations with your GM? As far as withholding or non-payment of salary is concerned, has it happened to you only or to many others as well?
The last question: was your duty station and the company's HR the same? If yes, then why not make a personal visit and understand what HR has to say? While you may send the letter, once the HR and Accounts departments refuse to take your calls, then do not expect them to take cognizance of this letter. Yes, legally, this is the first step.
I recommend you approach the Labour Officer (LO) of the area where your company is located. Explain your problem. Generally, cases of the managers are not entertained by the LOs; however, there is nothing wrong in trying your luck. If the LO lends weight to your case, your company will not be as intractable as it is now. The HR of your company will be forced to come to the Labour Office upon receipt of a letter from the Labour Officer. Sometimes, these matters are settled telephonically too. I have seen companies developing cold feet in front of the Labour Officer.
Thanks,
Dinesh Divekar