Airindia - Airindia denied to give refund

I booked tiket PNR no JF*HB and tiket no *************-** from Kolkata to Imphal on dated ** march ** and date of journey * April ** but airindia cancelled his flight .I requested many times through mail Twitter and talked customer care also but airindia denied to give refund and replied "who booked tiket before ** march is not eligible for refund ".But at the time of booking no any policy exists. Airindia issued advisory to travel same sector and same passenger up to ** september ** but I am not a frequent flyier and without any work why I travel .How airindia keep customer money without providing services. Other airlines formed credit shell or refund money so that customer utilize this but airindia do not wish to give refund/ service .so it is therefore requested that kindly approach airindia and resolve my issue .