Bad experience flying

I traveled with British Airway (Comair) twice - both times from Durban to Johannesburg and all I have to say is that I am NOT pleased with the service. The first time I had problems checking in on the app, also could not get through to the call center, arrived at the airport 5 minutes after check-in had closed - basically 40 minutes before departure, and my flight was canceled. I then had to book another flight but was also charged a fee???? You mean you could not help me because I was literally 5 mins late? The gates had not even opened yet!!! The second time they confused my gates so I arrived at the correct gate approx 15 minutes after the gates opened, still 20 minutes before departure and I had to fight to be let in and my luggage was already told to be canceled? This is absolutely terrible if you ask me and I though you guys were one of the best. Show me better man!