The "customer is always right" thing comes from an age of small, local businesses that employed a dozen people, and if you shop at those kinds of small, niche businesses you will very often still get that kind of service. Why? Because they can't afford to drive customers away, and the person who can authorize weird stuff is 10' away and glad to have an excuse to stop assembling boxes or scrubbing tabletops.
When you have a BIG business that employs tens of THOUSANDS of people, you need procedures in order to operate. Deviating from procedure on behalf of one customer means you have to be prepared to do it for ALL customers, and that's a HUGE FRIGGIN EXPENSE, especially since many of these "customers" wanting things are *in fact* thieves trying to scam you. It is not worth it even if one or two people throw up their hands in disgust and swear they're NEVER SHOPPING HERE AGAIN. Keep in mind that the way big box stores stay in business is by cutting expenses down to the bone, so they can offer low prices and the convenience that comes with enormous shelf space and one-stop-shopping. You can still get great customer service, you just have to be prepared to pay a premium for it, the same way you pay a premium for all premium services.
The really smart businesses are ones that figure out processes that allow them to give the appearance of catering without the expense. The online model, in many cases, offers superior opportunities to do this. Heck, I even prefer to order food online rather than call the restaurant because it takes only a few clicks to establish that I want NO BUN and SAUCE ON THE SIDE and the computer doesn't forget to ask for the expiration date on my credit card. The server isn't trying to man a counter and take calls at the same time, either, so it's not being interrupted every 3 seconds.
The idea that "the customer is always right" needs to die, not because customers are morons, but because it is a context-less commandment that doesn't reflect the type of business you're running or the *source* of your profits. There's a big difference between running a premium service and running a low-cost, mass-market service.