Korean Telecom Freetel hasn't existed as a separate entity since 2009, when they merged with KT. Olleh is KT's current corporate identity, so you might try contacting them and see if they can help you, though if it is locked to them, Apple's most recent information is that they do not provide unlocking services. I don't read Korean either, so you'll have to do a web search for a support phone number.
Even if they do, in most cases, though, a cell company will only unlock for the person with whom they had the contract, so if you purchased this iPhone used, as I'm guessing is the case or you'd know who it was locked to, you may not be able to get it unlocked.
Good luck.
Message was edited by: Dave Sawyer