British airways worst experience ever. Overbooking becomes my problem.

So, I am sitting on OR Tambo, Johannesburg airport for two days now. The reason why, is that they dubble book the seats on flights, hoping for no shows and now it becomes my problem. Everytime they promise me a seat on the next flight, it just never happens because there are no seats left. I was suppose to fly to London yester. They apologized, put me on the next flight, that did not happen and now again The person wearing a british suite, sitting on the other side of the counter, claims they have authority, not making my problem theirs. Not bother, not care, he is the boss and he can rule my life. On the other side people are waiting for me to start a workshop they paid for already. They took time off from their work, not really understanding that a company like British airways doesn't feel or evenbtry to help to put me on one of their flights. I also miss my second British flight from Heathrow to Belfast, that they tell me, is not their problem. How do you understand that. This is the worst ever experience I had ever in my life... Their problem becomes mine and they don't care. Just saying abig company doesn't really care avout their clients