Reservation of Ex serviceman

Good morning sir, I, Santanu Ghosh, a retired Air Force personnel. I retired on 28 Feb 2015. My enrollment date was 02 Feb 1995. I got No Objection Certificate on 04 Feb 2014 (One year before my engagement of 20 years expires) my regular engagement expired on 01 Feb 2015. As per notification of Staff Selection Commission CGL 2014, a serving defence personnel is eligible whose specified period of engagement will expire within the stipulated period of one year from closing date of notification My engagement expired on 01 Feb 2015 but I had to serve 27 days more till month end as per AFI 1969. Now when I am qualified for document verification/ interview it is written in interview call letter that ex serviceman must be discharged by 23 Feb 2015 as the closing date of notification was 24 Feb 2014. As per DOP&T OM of 1986 regarding reservation of ex serviceman the notification was correct but in interview/ document verification call letter SSC has mentioned the discharge date, which is controversial. As I got NOC to apply for civil post from one Govt. Organization and other organization supersede the rules. It is also a govt rule that date of discharge from any govt. service is on the last day of the month. I have also put query through PGPORTAL sight but SSC, DOP&T could not answered properly. I asked them to justify the word specified term of engagement and date of discharge.