Yeah... I worked at an officemax for a while and honestly when you sit at that register all day you tend to zone out and your mind wanders... it's kind of like a robotic routine, greet the customer, scan the items, spout the company enforcd question ("Do you need any extra ink or paper?") then bag it up and give them their cash/receipt asap.
So when someone tries to do something that breaks that routine, like asking if they can use several odd offers in conjunction, making you delete items/arguing prices, or in your case changing their payment amount, it sometimes takes cashiers a moment to "snap back" into the thinking world. Not saying that was the case with ur BB girl, just offering another perspective.
I swear retail sucks the life out of you...
So when someone tries to do something that breaks that routine, like asking if they can use several odd offers in conjunction, making you delete items/arguing prices, or in your case changing their payment amount, it sometimes takes cashiers a moment to "snap back" into the thinking world. Not saying that was the case with ur BB girl, just offering another perspective.
I swear retail sucks the life out of you...