Customer turned down

Today (10 December 2018 @ 21:55) I was at KFC - King Shaka Airport. I spoke to Lungy who I believe is a Supervisor. The lady refused to prepare our streetwise meal order saying that their pot are too big for our small order and that did not sit well with us. KFC is a huge brand and we expect world class service, and that was not the case in this store. How can a customer be turned away because your employees are rushing to go home? I need this to be addressed and feedback to me soonest.