So the business doesn't help the customer and the customer responds by being upset and rude. How is this supposed to be resolved?
When I worked in retail - both for other people and in the retail component of our small business - it became very easy to spot customers who were easy to work with and those who were gunning for an argument.
People who are difficult to please in arena of life tend to be pain in the neck everywhere. By the same token, folks who are pleasant and kind bring that with them to all their encounters.
Case in point: About 15 years ago the AC at the school (our host for the sale) was on the blink. Most of that day's customers had delayed until the last minute to buy required supplies for their children's return to classes a few days later. Mind you, we had publicized numerous previous sales at that campus over the summer, offering incentives and begging people to shop early, but as always happened a whole lot of people put it off until they could no longer do so.
Mid-August in Los Angeles, so over 100° outside and hotter still indoors with the AC on the fritz. Lines were long, and people who should have been irritated with themselves for procrastinating were taking it out on our staff (DH & me plus about 8 late teen staff members). Lots of snarky remarks and unpleasantness - and this by parents sending their children to a Christian school, no less.
Our staff was sweltering by a couple of hours in. One woman walked to the side of my line and said, "Oh my gosh, you poor things. I'm going to run over to Jamba Juice (5 miles away) to get you some drinks." I protested saying we had water bottles but she wouldn't hear of it. She walked over to each of our staff and took their order. I thrust $100 at her from the cash register.
She and her kids returned about 45 minutes later with a receipt, the change, and drinks for everyone plus a few to put in our cooler in case anyone wanted more.
Not one of us never forgot her kindness. When she'd come in from then on, we were all tripping over each other to wait on her. When her kids got older, we hired them on as staff.
People bring who they are with them through all encounters in life, and their behavior gets reflected back. Put employees on the defensive with rudeness, and guess how they'll respond? Engage them with a smile and kindness, and that will almost certainly be the treatment you'll receive.
Another example: My mom had died recently and I was going to her house to work on cleaning it out. Mid-morning, I stopped at Trader Joe's to pick up lunch and snacks for myself and my husband who was going to meet me there. The clerk smiled as he checked me out and said, "Looks like a great day for a picnic!"
A few tears welled up in my eyes as I quietly said that my mom had died and I was heading to her house to clear some of the stuff. He walked out from behind the register, grabbed a bouquet of sunflowers from the flower section, handed them to me, and said, "I hope these will help you get through the day."
The next day I called TJ to tell them how much that meant to me. The manager said he would mention to the employee, and bring it up in their next team meeting. He said TJ employees are intentionally empowered to make spot decisions and he was so pleased that the gentleman who waited on me had shown me such kindness.
You can bet your boots that I've remained a loyal TJ customer. Also that I'm choked up as I type this.