Dialing the wrong number is understandable. It's a common error especially with the touch screens nowadays. But I hate it when you get a call and immediately asked, "Who are you?" I mean you're the one who called me, be it wrong number or not, I should be the one asking that question. There are two things that makes this worse:
- Strong/impolite tone. In English, it's all about how you say it. The tone of voice delivers the question politely or not. In Korean (and most Asian languages), there are honorifics. "Eh, nuguseyo? (에, 누구세요?)" sounds a lot better than, "Nuguya!? (누구야!?)"
- Hanging up without a word. Not even an apology.
This is why I entertain telemarketers as much as their effort. What they do is mostly a nuisance to me, but they're just doing their job, after all. They open with a cheerful voice, you could see them smiling while talking. And end up with a nice apology after telling them I'm not their target customer.
As for those interested on what I usually say, this is the common dialogue:
"Hello?" (I always open with English greeting)
"Anyeonghaseyo blah blah blah"
"Chamkamanyo, cheon waegoogin yeyo (잠깐만요 전 외국인예요)" (Wait, I'm a foreigner.)
"Ah, chueseonghaeyo... (아, 죄송 해요...)" (and the rest of it towards hanging up)