The Coupon Karen
If you’re a cashier, you probably have a sixth sense for spotting a Karen from a crowd. For those that don’t know, a Karen will come into the store with a fanny pack filled with coupons. Most people have one or two coupons, but this Karen was prepared.
However, the majority of her coupons were expired, so, of course, the OP had to reject them. This didn’t please the Karen in the slightest, so she asked to speak to the manager while cursing a blue streak in the teenager OP’s face. After assessing the situation, the manager told her to get lost. You see, the customer isn’t always right!