Old Navy review: Customer service

We actually contemplated on putting in a complaint, especially as someone who works in customer service herself. But I feel it is needed, we were at the Muncy PA Old Navy about a week and a half ago. We picked up these shirts that said they were 99 cents for our son and when we went up to see if they were that actual price the lady that checked us out was very rude and belittled us. The sign should of been moved if that wasn't the correct price, but besides the point as she was checking us out she was giving us attitude and there was also no name tags present. We gave her a $50 bill for the items we did purchase and she ran it through the machine that checks if it is real or fake and obviously it went through but then she threw the machine at her register then picked her cell phone up and chucked that as well onto her area. We were not rude to her at all, we asked a simple question. I think her behavior was completely uncalled for, I've worked in customer service for years and even if I get a rude customer (which we weren't) I'm just making my point I don't even do things like that, because my job is to remain professional and to answer questions to the best of my knowledge in a professional manner. Which she wasn't at all. She should of handled the situation a complete different way her job is to check customers out and answer questions that are presented to her, my fiancé and I were very upset at the customer service we received considering we were not rude one bit and we were treated very poorly over asking a question especially in front of so many other people it was quite embarrassing and unfathomable. And it is frustrating I can't even say who she was because all 3 checking people out did not have a name tag present and I feel they should be for manners like this!