Earned/Sick leave transfer on joining one PSU to Other

Dear sir, I joined IOCL after my application forwarded through proper channel, and necessary N.O.C also taken from my previous PSU BSNL. Now my credit earned + sick leave is not transferred / not encashed by BSNL ...stating that " my resignation is not technical" and " BSNL is 100% central govt. owened company and followes CCS rules where as IOCL is following D.P.E guidelines". This is the latest clarification given by them... I am fighting for last 4 years for my justified right but each time BSNL - Nadiad SSA, Gujarat is giving various reasons to harass me and not getting my case solved ..please guide me what to do..as my too much time vasted and it is creating psychological pressure and deep disappointment to me... I have lost faith in this govt. System.....and also give me correct n clear idea about" technical resignation" as they are denying all the statement for it available in CCS rules as per the Swamy's book.. Seeking for your valuable guidance in this matter...please help me sir... Regards Prashant parmar