Noc is not given by the present company

SIR, I AM WORKING AS ASSISTANT ENGINEER IN GOVT OF INDIA AUTONOMOUS BODY DAMODAR VALLEY CORPORATION(DVC) SINCE 26.12.2011. WHEN THE VACANCY ADVERTISEMENT CAME IN PAPER AND ITS WEBSITE FOR THIS POST THEIR WAS MENTIONED A SERVICE AGRREMENT BOND TO SERVE THE CORPORATION FOR 02(TWO) YEARS OTHERWISE TO PAY 2 LAKH FOR BREAKING THE AGREEMENT.AFTER EXAM AND INTERVIEW ,I WAS SELECTED FOR THAT POST AND GOT THE APPOINTMENT LETTER IN THIS BOND AGREEMENT WAS WRITTEN FOR 4 YEARS AND FOR BREAKING 2 LAKH + SBI BANK IINTERST AT THAT TIME. I HAVE JOINED THE POST AND GIVEN A WRITTEN LETTER REGARDING THIS CHANGE,BUT I GOT ONLY THE ANSWER FROM THAT SIDE IS ITS WAS MISTAKE FROM COMPANY ,ACTUAL BOND IS AS PER THE APPOINTMENT LETTER.NOW I HAVE APPLIED FOR THE NO OBJECTION CERTIFICATE(NOC) FROM THE CORPORATION FOR THE ATTENDING IN THE INTERVIEW OF THE BIHAR PUBLIC SERVICE COMMISSION ,A GAZETTED JOB OF BIHAR GOVERMENT AND BETTER THAN PRESENT JOB. I HAVE APPLIED THE BPSC BEFORE JOINING THE DVC. THE CORPORATION HAS DENIED TO GIVE NOC AND SAYING THAT NOC IS NOT GIVEN IN THE BOND PERIOD.I AM READY TO PAY THE BOND IF SELECTED IN THE BPSC AS PER CORPORATION BOND.WHAT I WILL DO, PLEASE HELP ME.