Customer complaint

I am writing this letter to express my disappointment in British Airways and the lack of service I have received. When I booked my ticket on the 13th of December, I received my booking confirmation from Travelstart (ZA***4) confirming flight BA 6217 from Johannesburg to Durban on the 2nd of January at 14:15. The morning of the 2nd, I checked in online but noticed the flight time had changed to 15:50. I was never informed of this. I then requested the boarding passes to be emailed to me. I never received those emails. I then had to save them and get them printed as I wanted to check if there was some problem with the departure time. I then called the following number ; ***, to check what the reason was but I was on hold for about 30 minutes before I gave up. At the airport, I went to the "bag drop" desk and I asked the lady behind the desk what was going on, the response I received was very rude and unprofessional. She basically told me that IF my flight was really at 14:15 I would have missed it anyway and that she did not see any flights scheduled for 14:15. Not only was I on the phone and laptop for most of the morning, trying to figure out what was going on and trying to get hold of someone at customer care, but then we had to wait at the airport since our flight was delayed on top of the other issue. Not only did it inconvenience a friend who fetched us from the airport, but I planned my trip to be home at 17:00 because I don't like traveling with my child in the dark. We only reached home at 20:00. I understand that flights get delayed for various reasons but I honestly thought British Airways would at least inform a customer of departure time changes.

I receive "undelivered" replies to all the email addresses I found online to log a complaint to Comair South Africa so I had to revert to Hellopeter. Why is it so hard to submit a complaint to them directly? I have proof of the booking confirmation time of 14:15 as well as the boarding pass with departure time of 15:50.