H1B Undertaking fulfilled, but employer still is forcing me to pa

His issue is with respect to my previous employer. 1. My previous employer in, Chennai, India, had deputed me on AUG 2015 for an onsite assignment to USA at a client, Hesston, Kansas. 2. I was asked to sign an "H1B FOREIGN ONSITE DEPUTATION UNDERTAKING", in India, which is attached herewith on JULY 2015. 3. After the completion/closure of the assignment and finishing all the formalities required by the company in DEC 2016, did I resigned 4. They wanted me to come back to India for 3 months and do knowledge transfer for the employees there, which I was unable to do, nor was necessary for reasons mentioned below : a. The Offshore team was dissolved on 30 Nov 17 b. I was carrying out the same work onsite in USA that I was doing offshore in India. There was no additional or new work or training provided for this. So there in no new knowledge acquired which is to be transferred. c. Further I was unable to travel due to my personal reasons : i) I had a 2 month old baby who had not yet got his passport or travel documents. ii) Secondly my wife who had a C-Section operation was not fit to travel. All the above was explained to them, but they are insisting that I should pay the 'pre-estimated liquidate damages' of INR.500,000 as per the undertaking. They are dragging the matter for the last 7 months. Please let me have your opinion on the above. Essentially I would like to receive: A. Waiver of the liquidated damages B. More importantly my Relieving Letter, Experience Certificate, Gratuity and all required documents from my employer. Please let me know if you require any further information.