Employment bond

Hi Sir Currently I am working in an Bank and have signed a bond of 2 years and a 3 months notice period .If i am willing to break the bond i would have to pay 1 lakh ,After I completed my probation, I requested them a loss of pay leave(Extra Ordinary) for an year for UPSC preparations. Initially the management assures the said leave(unofficially) and sanctioned an initial 3 months LOP leave.Now they are asking me to join immediately as my leave period of three months is over, As in the midst of my preparation I want to resign from the bank to be in a state of peace for my studies but I don't have enough money to break the bond. What if they terminate me? .Can i demand an experience certificate if they terminate me ?(so that only I can produce the experience certificate to interviews)or can they go for any legal procedures to recover the money?What are the options available for me to resign the job with a relieving letter or an experience certificate without paying the bond money. Kindly provide me with your thoughts Thanks