Well, most Thais are usually very calm, even in a confrontation (which they try to avoid). They have what we refer to as a "mai pen rai*" attitude. I, on the other hand, am not Thai and I am not always very calm. I don't let things slide and I won't put up with nonsense, especially when I'm paying something.
I really got to know them earlier this year when I was on the phone with the 5 times a day trying to sort out some issues between True, Blizzard Entertainment, and a bunch of World of Warcraft players who use True. True introduced some minor throttling of certain protocols (mostly BitTorrent stuff), and this somehow affected WoW's semi-proprietary protocol (they use a modified version of something, I can't remember the details now). Anyway, after 3 weeks of helping True sort it out over the phone and also trying to coordinate discussion between them and Blizzard, people get to know you. I also ripped one of their customer service reps a new ...hole for being rude and trying to lie to me once. It's actually a really long story, like I said, it went on for weeks. Documented and buried on the WoW tech support forum somewhere.
I came to the realization that they all knew me when I called them one day, got some person and they were like
"Thank you for calling True. What is your telephone number?"
"02-345-6789"
"Your name?"
"Quaxo."
"Oh, hello again Quaxo (not my real name). You're calling for the supervisor?"
"Um.. yes. You know me?"
"Yes. Everyone here knows you."
*mai pen rai (ไม่เป็นไร) has many uses, something to the effect of "nevermind" or "don't worry about it".