Rude and condescending staff who ignored customers

The branch was quiet when I arrived at 2pm.Most of the employees are sitting at their desks with no clients with them.I waited for more than 20 mins and noticed that the queue was barely moving. 2 customers have already complained and there was no one around to coordinate. Eventually, I reached the counter and was told that I needed to joining the queue again for another matter. This is when another 2 customers got angry and tried to leave. A staff member finally showed up, but instead of apologizing and tried to calm the customers. She was irritable and raised her voice. The angry customer who tried to leave threw the ticket on the floor. To my surprise, the staff member pointed at the paper which landed next to her feet and shouted at the customer to \come pick this up". I then confronted the staff member about her condescending attitude and lack of empathy but I was told to get out or stand aside. When I approached the manager"