Poor service

@British Airways OR Tambo International Airport, I am flabagasted by your code of conduct. Yesterday I was supposed to have boarded your flight to Heathrow London(7:45pm) and all I received was utter disgrace from the checkin staff. What was more disgusting was their refusal to allow me to see the supervisor or manager in charge and the reason I received was that I should approach the UK embassy to get a VISA for traveling. This morning the UK embassy in Gaborone is surprised by what British Airways is saying and that I don't need a VISA to travel to the UK. Further more the Ministry of Foreign Affairs was approached and they are also intrigued by the verbal reason given by the British Airways personnel. Both the embassy and Ministry are seeking written reasons for the rejection of boarding the flight but I seem not to be getting any assistance by your officials here at the airport. It is day2 stuck at the airport and to this moment I am being sent from pillar to post. Even when asking for protection of my departure ticket is going invein, it looks like I am being taken for a ride and I'm highly disappointed.