Very bad attitude.

My wife and me flew from East London on the 30th December 2015 to Johannesburg. Departed 10.45 Booking Ref W6R3QQ We arrived at the airport and wanted to be seated on the wing opposite the doors as there is more legroom there. We were told that we were already allocated seats so we asked them by whom? No answer. We were then told by the lady doing our checking in that there were seats on the wing but she would have to get the supervisor to do the change. The supervisor eventually arrived and was she a piece of work. Down right rude!!!! Told us due to weight distribution she could not change us. I will never fly with them again. I don't need this in my life. I will pay more and not be treated like trash.