Confused and dissatisfied with the service I received🚮

Please help me make sense of this, why do You need to have the MacDonald’s app in order to purchase a R9.90 Ice Cream?🧐

Yesterday at MacD in Sandown opposite Sandown High School we walked in with my niece who’s was excited to have some Ice Cream just to cool down after our casual walk in the neighbourhood and as we walked inside MacD 1st of all the service was trouble🚮, no one bothered to even greet us, as we approached the counter to buy 2 ice creams that would’ve cost us R20 and I had R100 cash in hand and holding my phone in the same hand, the lady who supposed to serve us, I don’t know why she had attitude🤷🏻♂️, she said to us and I quote “You can’t buy those over the counter you need to have the app to buy those” with so much attitude, I remember seeing my niece’s disappointed face🥺 after we were told that, I did not even bother looking at the lady’s name but I thousand percent remember her face.

We walked out MacD extremely confused and dissatisfied😞 because help me make sense of this situation, 1st of all not everyone owns a smartphone to download the App she was talking about in this economy we’re living in and 2nd of all what if it was just an older person and all they wanted was just an ice cream were they gonna be told the same thing??🧐🧐