KFC Rifle Range - Disturbing Customer Service

Just been to the KFC at Rifle range and experienced the worse service possible. The lady, Alda at the order window shouted at us for wanting to change our order. All we wanted was to add a 2 litre coke to our order! We are regular customers at this particular branch and it isn't the first time we have experienced this sort of service. Disappointing from a brand such as KFC!