After some time of mailing with Tele2 swe operators support I've collected all information they needed to factory unlock my iPhone 4.
They told that I'll need to use any swedish sim card(specifically NOT Tele2 or Comviq) to complete unlock in iTunes(only use once and that's it).
Why? Can I just jailbreak instead activating it? Or this is essential part of unlocking?(I have no experience of factory unlocking and was struggling all the way with support service all by my own).