Cancellation of Flight 7 weeks before holiday

Good day, in April we planned and booked to go on holiday already for first week in October as we knew its school holidays and flights will be fully booked. Our flight number was E4887P. Today, 7 weeks before the holidays I get a notification to state our flight has been cancelled as it did not make business sense. How on Gods name can school holidays when people travel not make business sense. Then to top things off I search on other airlines just to find they fully booked for our date of travel and Safair has the nerve to say the payment I paid with my debit card which they so politely took immediately might take up to 21 days to refund. This would of been our first holiday in 4 years and you guys have managed to f it up. Thanks for the awesome service. I guess low cost airlines mean low cost service. And even if I could get a flight now it would be triple priced as its so late and holiday season. People plan their holidays just for you guys to mess it up. I want my refund immediately. Disgusting.