Employer is not giving me proper noc for m phil

Respected Sir/madam, I am working as Faculty member in teaching institute where it’s very important to do M.Phil/PhD as early as possible. I had applied for M. Phil course in April 2016 by just informing my employer that I am going to apply. Selection process took time and interview was scheduled in May 2017. Before interview I applied for NOC from employer & tried to get NOC but employer didnt issue me NOC. Instead they asked me few questions about the course by issuing letter which is been answered by me with documents. I am regular employee and my probation period is completed. In my appointment letter it is mentioned that I have to get NOC for higher education. In NOC request application I mentioned I will take leaves from my account and leave without pay (if required) and I don’t require any additional favor from the institute but I didn’t receive NOC. I was not expected but in the month of Feb 2018 I received M.Phil admission letter in which "admission with effect from April 2016 is written which means session 2016-17(I was unaware of this while applying)". This is M.Phil by research four year degree so I need not to complete course work but I have to complete research assignments which require less numbers of leaves (days). Now Principal of institute also changed and I was confused how I should proceed further. I have decided to meet Principal and told everything but slightly hidden the fact saying admission is in progress & is require NOC to complete it (I thought if I say everything truly he will scold me & will not process my request) and requested to issue NOC mentioning my date of application as April 2016 in it but 1) My Principal is denied to issue NOC and said he can issue NOC mentioning session 2018-19 which is not useful for my above mentioned degree. Principal said I am new & I don’t have interest to see your past request for NOC 2) Even I am requesting NOC on the basis for leave they are asking for very severe/harsh ‘surety bond’ of Service Period of four years after completion of degree OR amount deposit equivalent to four years salary in case of any default (four years is a period of my M Phil degree). 3) There is one sentence in surety bond mentioning “If anything is hidden by candidate OR false information found he/she will be terminated”. This sentence is against me since I am hiding some real facts of admission status Respected Sir/madam, please guide me how should I proceed in this issue to get me proper NOC to proceed further. I don’t want to miss this degree since it’s on the basis of old rules & it’s not possible to get admission it I apply now with new rules. Thanks & Regards S. Kumar