Dollar Tree

At store #2632 I walked in at 12:45pm simply looking for some chips. I know this place isn't know for its incredible customer service but i walked in to no one in sight of the registers at all. I was simply assuming it was short staffed but the family who walked in before me was fuming loud and upset as they couldn't locate an employee in the store. Me hating confrontation and feeling bad that the store was short staff decided to look for the employee and let her know there was a line forming and a very irate customer. When i located her, she was working and i quietly let her know there's a line forming of people. She got very snappy with me and said "there's a bell they should've rang" I was immediately taken back by her rude response instead of a simple thank you. When i returned to the register she didn't speak to a single customer just rushed us out and gave us our totals. The store immediately felt unwelcoming and i just left not wanting to ever return. I hope some one explain how to interact with customers to her. Being a previous customer service representative i know it suck to have the unfortunate job of running the store by yourself but a simple "sorry about the wait" and "how can i help you" or even a "thank you for letting me know" would have been way better and recovered the entire situation.