Prorata Pension

I had worked in ISRO GOI from 1977 to 1980 joining as Scientific assistant B and got promoted to Technical assistant C in the year 1979.As I come under scientific staff I was subscribing to cpf by ISRO and switch over to gpf option was left open. I joined CMCltd in 1981 after I got relieved from ISRO vide extant OM 1976 and ISRO credited my CPF contributions with interest to my epf account at CMCltd.As per OM1976,I had opted for prorata pension on my confirmation at CMCltd.Subsequently,as OM 1976 has disparities,GOI had issued another OM1987 ,ceasing the OM1976 operation and those absorbed in public sector can avail pro-rata pension for Government service or pension for combined service if permitted.cmcltd wrote letter to ISRO and DOPPW to return my cpf contributions back to ISRO to avail prorata pension from ISRO.There was no Reply from ISRO. Then in 1989 , as I was not well and after obtaining more than ten years of qualifying service I had resigned to my CMCltd job with a hope that I get pension from ISRO GOI There on I worked in couple of companies subscribing to eps95. On my superannuation in 2012 I had approached CMCLTD and ISRO for prorata pension