Dollar Tree review: customer service

I went in to grab some items. When I went to checkout, there was no cashier and another couple in front of me. We waited for a little while, and I notice the guy was annoyed too. As I kept looking around for someone, I saw that there was an employee helping a customer with balloons. There was no way she was the only employee here. So, I went looking for someone and found two other employees in the back. I asked if someone could ring us up. One of the girl rudely said "No, we're unloading boxes here." In my head I'm thinking, "Okay, that's fine I guess." What bothered me the most was when I walked away she said to her coworker, "Can't she see that we're unloading here?" At that point, I was honestly mad. They couldn't rings us up which would only taken a few minutes, but they had time to talk. This was such horrible customer service I experienced so far. I went to put my items back and left. I understand the importance of getting stocks on the shelf since I also work in retail. However, serving the customer should come first. Customers come and go, but the stock will always be there. Additionally, if you have something to say, you wait until they were actually gone before saying something.