No refund - Sandton City Flight center.

My husbandand I booked tickets for the two of us , our two children and my mother for Johanesburg to Mumbai and back . Our trip was meant to start on the 23rd December 2016, unfortunately my Father in law passed away a week before our trip so we cancelled the trip a few days before scheduled datesI was asked to send a death certificate so that refunds could be processed ,which I sent the day before our scheduled travel date. According to the flight center agent that assisted us, only my mothers was refunded to them. My mother although booked on the same flight as us was booked on the codeshare airline seat. To date we do not have received any reason regarding the delay . It is now a year and 4 months later . Ref number 4IZML3