Kulula employees change rules as they please... At the expense of their customers!

Dear Kulula management. I would like to express my disappointment with your staff around our flight from Johannesburg OR Tambo International to Port Elizabeth. My flight was booked though Kulula.com and is operated by Comair flying with British Airways flight BA6239 (4 June 2018). Firstly, the flight was delayed. Given this was due to the fog around Johannesburg on the day, this we all accept. The problem is that your staff decided to change the rules of boarding just as they like and that at the expense of your customers. Due to the delayed flight, the boarding was also delayed (NOT SHORTENED). Boarding started at 18h15PM. This you can see is clearly indicated on the records as I was shown the boarding page that one of the ladies carried around. I arrived at the gate at 18h24PM only to be informed that the boarding is closed and that I have already been offloaded, together with the two people standing directly behind me. This all in a fast forward 8 minutes from when boarding started. What ever happened to the 15 minutes boarding time? Since when do the staff have the right to decide that 8 minutes of boarding is enough time before they start offloading passengers? To make matters worse, we saw the entire line of passengers still queuing in the loading isle as the doors of the plane were still closed. As mentioned above, this was all at the expense of your customers that paid for their tickets and chose you (Kulula) above the rest of the airlines. I fly Kulula a lot and this was the first time I have been let down to such an extent. It took probably 10 calls to supervisors to tell your staff that what they are doing is wrong. We were eventually let through 15 minutes later after a massive fight and bad attitude by your staff, just to join the que for another 20 minutes before the doors of the plane opened. This level of service for flight BA6239 is really unacceptable and according to me should be seriously addressed with your staff. Why should I or anyone else for that matter fly Kulula if your staff or partner carrier staff change rules as they please at the expense of the customers?