Reservation of obc

I applied for the post of PGT (English) in Novodaya Vidylaya Samiti (NVS) 2014-15 as an OBC. OBC had zero vacancy. I got age relaxation of 3 years (My D.O.B. Oct 1971) and was allowed to apply, to appear in the exam as OBC and in the interview as General. I secured the cut off marks stipulated for general category. (DoPT says: Only such SC/ST/OBC candidates who are selected on the same standard as applied to general candidates shall be treated as own merit candidates. If any SC/ST/OBC candidate is selected by getting any relaxation in experience qualification, number of permitted chances in written examination, zone of consideration etc., he/shes hall be counted against reserved vacancies. Such a candidate cannot be considered for appointment against an unreserved vacancy.) My allowance by the NVS put me in the thought that I was relaxed by age to compete against general category. In a later order of DoPT says:Only such SC/ST/OBC candidates who are selected on the same standard as applied to general candidates shall be treated as own merit candidates. If any SC/ST/OBC candidate is selected by getting any relaxation, AGE LIMIT, in experience qualification, number of permitted chances in written examination, zone of consideration etc., he/shes hall be counted against reserved vacancies. Such a candidate cannot be considered for appointment against an unreserved vacancy.) Now NVS denies my appointment (RTI filed by me) saying that I do not fit in general category. Should I have run to find all the laws and orders of DoPT before applying for PGT(English). NVS and I both were aware of the ZERO VACANCY' for OBC. Yet it allowed me from application to interview and at the 11th hour the denial. What shall I do ?