Help I want to cancel my flight and seems like there are no staff

I am booked on a flight for tomorrow, I have been trying for 3 days to change my bookings, now to cancel it as they had delayed the flights 3 times and it was no longer practical for me to fly, I have been on hold for over 3 hours in the 3 days, cant change anything on the app or website, when you email the email address does not work, I am at a loss I am not sure what to do I want to cancel my booking but its an impossible task please help is someone has a chance I have spent hundreds of thousands of rands flying British airways and am highly disappointed