McDonald's Staff Discriminating

Let's make Sipho who works at Mcdonalds Epping Famous. So this girl thought discriminating me was a joke to her. My brother in-law and I stopped at the restaurant for something to eat. She took our order and while she was waiting for the slip she asked how are we related, I responded "His my brother in-law" and she tells my brother in-law "I thought this was your daughter". She did not even apologize. I said excuse me and she walked away. If I were to call her the "K" word. It would've been on every news outlet this morning. McDonalds your staff can do serious brand damage. I will no longer support McDonalds ???????