Chem Air Cancelled flights difficulty to get a refund

I booked a flight with Chem Air to fly from Johannesburg to Margate on 20 December 2018' We where informed that all flights were cancelled by Chem Air prior to the date above .

We contacted Chem Air and have been told that we can expect a refund on the 11 March 2019. I find this very disturbing as I am a pensioner I had to buy an alternative ticket to Durban and arrange transport for my son from Durban to Margate at extra cost .

So paid for two tickets plus transport to Margate and am now told I must wait for a refund until the 11 March . Please help .