Visa agreement in corporate secor

I work in an IT company in Mumbai. The company had promised to send me abroad and they filed my work permit for Germany. I was asked to sign a Visa agreement for 1 year which had the below clauses. 1) Bond stands valid if the visa gets processed. 2) Any violation in the bond, the candidate will have to pay Rs 2 Lacs to the company. 3) Bond stands void if the visa gets cancelled. The Visa was filed and it got processed. However I was not sent abroad. Also the Visa got expired now. I resigned from the company within 1 year of the bond as I had got a better offer. Now my previous company is not providing me my experience letter and my salary for last month. They are asking me to provide a the bond amount of Rs 2 Lacs without which they will not provide me my experience letter. In my case, 1) I was not sent abroad after the visa was filed. 2) The Visa expired before my separation from the company. Please let me know what can be done in this case. Will sending a legal notice help? Any kind of advise is appreciated