I still remember doing a shop at a grocery store near me. At the time, it was the closest store to where I lived, and was where I did the bulk of my grocery shopping. There was a customer service rep there who was ALWAYS unfriendly and usually confrontational unless it was a very simple inquiry.
The shop required a visit to the customer service desk to ask a question, which I did early in the shop with no issue. When I checked out, an item scanned at the wrong price. There had been a tag on the shelf but the item was advertised at a lower price in the circular. It was a new variety but it fit the size parameters and the ad said "all varieties." I went back to customer service, where I was assisted by this unfriendly rep. I was fought tooth and nail to get this issue resolved, which ended with me getting the item for free. You would have thought the money was coming out of her pocket. I was very pleased to be able to put all of this in my report.