Mango the non re-funders

My wife's flight got delayed 3 times on the 10/24/2019, booking reference SVSHGV. She went to OR Tambo Mango desk and requested Mango to cancel the booking because she could not be any later than she already was for a business meeting in KZN. She managed to book a flight on another airline. They confirmed that she would receive a full refund within two weeks but up to now no refund just empty promises and lies from the call centre agents.