Cancelled flights.

Flight booked on CemAir Bloemfontein to Johannesburg just cancelled. Had to book additional accommodation and car hire. No refund after writing to the complaints email address. Not even a return email. Worst service ever. My college flew back with Airline on the day my flight was cancelled and there were open seats on her flight. I asked about this and why we were not transferred to that flight. The answer was we do not have an agreement in place with then. Use a different airline where possible.