Cancelled flight with no effort to rebook or refund

On the 24th of September, my wife was meant to fly to cape town for a wedding on the day. 3 hours before her 9am flight, BA sent a message to cancel (with no effort to rebook her on another airline). She arrived at the airport to queues of people, with the BA staff saying there are no other available flights until there 2pm flight 5 hours after the initial departure time. I rebooked another flight for 9:15am with Safair. I have spent two weeks trying to get through to them (wasting my time and money), for the assistant to tell me I am only able to claim the original cost of my flight. Had I known how unreliable they are, I wouldve been able to lock in a better price 2 months ago when I booked with them. Worst airline.