Dunkin’ Donuts complaint: Bad Customer Service and no respect to Customers

I took my kids this morning to Dunkin doughnut at Mathews location, my daughter ordered a drink and she ended up not liking it at the first sip. I asked her to go back to the lady and asked please can you change it for me. My daughter returned back to me and said the lady told her no. I went to the lady and asked her kindly please can you change the drink for her she didn’t like it and she will not drink it, the lady was talking inappropriate to me and said oh no I’m not changing it and I told that to your daughter. I asked her this is not the right to talk to a customer, please I need to talk to the manager, she said I’m the manager. I told her if your claim is true you should be more respectful when you are talking to a customer. She wanted to argue and rose her voice, and said not everybody is not liking the drink we can change it. I told her any customer has the right to changereturn the product if heshe doesn’t like it, it is only one time, not asking for multiple times. The lady was saying to me what do you know about rules in a disrespectful manner. it was pointless to argue more, I picked my daughters and left.
This is so disrespectful, and shouldn’t be that way. If she can’t change the drink she should say that in a kind way.