Disgusting service, or lack of

Macdonald's Beyers Naude is most unhelpful. I ordered 2 R10 cappuccinos. They refused to sell this to me without me having the Macdonald's app. I have however bought the same on numerous occasions from them as well as other Macdonald's outlets without the need for the points on the app. Cashier showed absolutely no interest in trying to assist even though I mentioned this to her.