I'm sorry you had to endure that and put on a smile and be cordial through it all. It can be very tough.
I've run into a few here and there. I work in the utility industry, dealing with individuals, builders, dealers, etc. Most people are understanding and at least cordial. I try my best to do everything within my power to accommodate within reason. I do it because I enjoy helping and most people aren't shit weasels, but are just going through a rough patch and I happened to be the next "bump in the road."
When I do run into the infrequent shit weasel, it's truly a comedy you want popcorn for while you watch. When they've reached the point that I'm no longer willing to help them, I have policy, procedure, and the Public Utility Commission rules right behind me. They will literally push me into a corner, and then I'll just step aside and let them literally beat their head against the wall that is government bureaucracy.
I'm actually proud to say that I can count the times that has happened on one hand. I agree that the current "Me first" culture and mentality that is being fostered is churning out more entitled people. While I hope they don't turn into shit weasels, only time will tell.
One can have some fun with shit weasels, play their little games, or make out that one is playing, manipulate them and all and that can make the entire situation a little easier to deal with. Some are just total dick heads.
It's good to have some policy and procedure in place and available for when things go a little too far and it's amusing to watch these idiots beat their heads on the immovable wall of legislation, regulation and policy.