Whose Line Is It Anyway?

Knew I was in for a weird day when less than half an hour into my shift, crazy ass woman came to me wanting to buy a gift card. Pointed her in the direction of where they were and proceeded to serve next person in line. Crazy woman returns and I cash out her gift card and serve next person. Crazy woman proceeds to stand next to Express and after finish serving the next customer, then proceeds to put items on counter and asks me why I was so rude and served other people in front of her. I tried to explain that I thought we were done since I had sold her the gift card. Instead of putting her items on the counter, she keeps the cart across from her next to another till, buys the gift card and then gets out of the line. To me that means we're done! Logic didn't seem to work on this lady, even our interim Front Manager tried to talk to her but that wasn't good enough for this thunderous twat and demanded to speak to store manager. Dear crazy ass people, stay home.