When I did not hear what I wanted to hear which was he was no longer employed by them he has cost them many long time customers. Even with the offer of steep discounts on my next purchase I told them if I had the chance this service person ever came to my house I can't risk it. So you did not only lose just one customer but ever single person I know. Fire him or you lost me. Reprimand is not enough.
When I used to work at food joints. I always stepped up and served as the "glue" man. "Something wrong boss? Let me do your worrying. Goes South, pitch me out."
To me that has always been "the way an employee is to be". What usually happened though was completely the opposite of me being pitched out. I brought in at least 1,000 stable customers who might even suggest to ten, fifteen others to come in where I was, get good grub, service, clean place to eat.
I brought "rain" into businesses & people actually tried to actively recruit me, poach me away from here or there. Could do it no matter the menu, no matter the rest of the staff, I come in and worked magic. No, I was never a gourmet nor do i ever desire being. I was at best a cook, maybe not the best cook but cooked well enough I fed to my family. Every other family saw that, come and adopted me.
Long about age forty two to forty four I realized that I just can not "move" to do the back line work any more. Until then I "danced" around three, or four seventeen year old kids at a time. My training them consisted of "here fall into the deep water, swim!" I learned from a lady once that if someone does not "get it" after three days, send them out. She was correct too, until she was not and lied to me about what was coming.
The point I'm making is that, I do exactly the same thing with businesses, people. I take the silent route though. If you normally take care of me well but one time you goof up for whatever reason, "okay, just give me a sorry and try to not let it happen again." If it starts to run into being the usual "crappy" service, I start drawing away my business in steps, a quarter, fifty percent, seventy five percent, then I'm gone and you'll not see me again. Note, you give them opportunities to make corrections at each step back. If that does not happen move to the next step back.
I do the same with people. I play "baseball" three strikes and I walk away from someone to be gone, probably forever, unless they realize later they screwed up and change. Although, I also play innings, all nine with people on an individual level. That gives them 27 strikes, or two foul tips and a strike in an inning. I allow for balls as well, maybe I read/did/said something wrong, maybe it was Universal Interference. So, all in I think I act fairly with other people.
Up to the point they start acting unfair toward me, or abusive to others. at that point they can forget playing "ball" with me, cold rage politely escorts them to the door and if need be LEO's may offer an assist. I won't resort to violence unless it is the last resort. I can not "get angry" and "let it go" like most people though. I am too passionate with anger and literally black out, do damage, come to and not recall a thing. Granted I might try "diminished capacity" but that will not be allowed in my case. I've been too trained and I am aware of my anger problem, ergo am accountable even if I do black out. Yep, know if first hand factual.*ahem*
So, I concur with what you are doing taking business away from them & spreading "word" to others to avoid doing business with them. That is not using anger directly but rather assertively and constructively to create businesses that do understand and value professional accountability. You do not get mad, you get even. You cut them by taking dollars away.
You may want to check out
B Corporations. They have a link there to a directory of various corporations coming into the B Corporation structure / mission plan. For a long while I used DuckDuckGo, still do to some degree but now most of my searching is
Ecosia. They are planting trees out of money they make offering search services, or rather the adverts served, but unobtrusive text based ads. Granted you need to do 45 searches to plant 1 tree, I've already planted 6 trees though.
That also goes to fund women's businesses in parts of Africa as well. They get a "bank" from pooling a few dollars here and there from their tree planting paychecks. So searching on the Web/ Internet has started to help heal our world.
See? I'm telling you Love wins. All we need to do is let the Light shine on the evil, then hold fast to the good. And if the evil gets mouthy with you, tries stupid stuff against you, send it my way. I eat monsters. They are tasty and fill my belly well, and I then make more good with the energy from them.