Locked in bus on tarmac

I was on SA 1775 to Gaberone on 28th April 2015.<br> 2.We were kept in the bus next to the plane with the driver in his seat and his door open and the controller/check in person, who had sat next to the driver outside, next to the plane. <br> 3.We were kept in the bus for 15 minutes with no air conditioning or any air and all the passengers were experiencing problems with air and heat. We were banging on the doors and windows and both the driver and the controller person just looked at us and ignored us.<br> 4.This was clearly a health hazard and we were all sweating and about to faint when they opened the doors and let us board the plane. The Hostess even had the air on cold and high and apologised, yet the driver and the controller person were not interested.<br> 5. This affected my blood pressure, for which I am on medication and due to this, I was held up with a medical problem in Gaberone and thus could not complete all my business.<br> 6. This was not well received by my client and I may well have lost business due to this.<br> 7. How can anyone lock 50 or so people in a hot bus in the heat of the day without any air. This is a crim