I'm sorry this happened to the OP, it is a real kick in the pants to be treated poorly.
As someone who has been on both sides of this equation (customer and dealer) I understand and sympathize with both parties here. When I was in my early 20s I walked into a showroom for a store with a solid reputation and asked if I could check out their turntables. The salesperson, who was involved in a discussion with fellow salespeople about some sportsball event responded to my request with a casual thumb jerk, stating "turntables are over there" while barely pausing his conversation about bad calls by refs and other related pressing matters. I had saved about $10K and was excited about getting into this "hobby" for real, and it really took the wind out of my sales to be treated like a schlub. A year or so later, I was looking for a "basic" job while I was completing my time in the old college meatgrinder, and applied at the same audio store. I got the job, and was thrilled to not only be gainfully employed, but actually getting paid to listen to and recommend audio products, the sole purpose of which was to bring some joy into clients' homes. The guy who had dismissed me still worked there, and I reminded him of the event. He didn't remember it (funny how things can have such an impact on one person in a transaction but none on the other) but was embarassed by it and it made an impact on him when I relayed the story. I, on the other hand, now understood why someone could be so cavalier toward a potential customer. I still recall the first time I spent time with a customer who wanted to hear a system with this DAC, then that preamplifier, then with this phono pre, then with that IC loom, and so on. After about 2 and a half hours, he pulled out a sheet he had printed at home with an online dealer (who I had never heard of) and asked that I match the price of about 40% off retail for the phono preamplifier. This was in the late 90s, so the internet was still a bit of a novelty, especially for shopping for high end audio. I was rather curt with my reply, and offered a discount at around half of what was being asked. The customer declined and said he'd buy it online. That customer become persona non grata in our store after that, and I would guess he went on to burn bridges at other dealers after wandering around our showroom and being treated like the schnorer he was. Having said all that, to this day I treat every customer with the same level of respect, regardless of fashion sense, age, or gender. By giving everyone the "benefit of the doubt", one will (almost) always get the same treatment in kind.
So the problem isn't JUST online dealers or online-buying tire kickers, it's the willingness of consumers to trade bargains for service. The Walmartiziation of the world resulted in a warehouse culture that is more interested in market share than client relationships. It's a vicious circle.