Earned leave encashment

Sir/Madam,

 I served BSNL (PSU)for 3yrs and nine months including 2yrs of probation in group c cadre, i later joined BMRC (PSU) through proper channel including NOC from BSNL, i am left with 75 earned leave (EL)from bsnl and as per CCS leave rules i should be getting complete EL encashment at the time of resigning under CCS 39 D leave rules, however my employer as refusing me EL encashment.. it is been 1.5years since i have resigned. How to proceed further.

Regards.