Pethetic burger King Cavendish Square

Really bad service at burger King Cavendish Square, Claremont. The cashiers were very slow (which is understandable if they are training). However the problem was recieving my order. At least 4 people that ordered after me, recieved their order before me. (I'd understand if it was smaller orders than mine but these were family meals and I ordered a plain burger and chips). Upon waiting the assistant manager asked me what I'm waiting for then I said "my order" and she gave attitude. Again still waiting for my order someone else got their order before me again and that guy told her to give his order to me rather because I've been waiting for a really long time. Then the lady gave attitude to him as well. There has never been a problem with this branch up until recently and it's extremely pethetic and unacceptable as I am a regular client to this branch.