Machang the best thing to do is go to one of those "phone doctors" in fort, they can do anything. and i do mean anything, I've seen them repair phones which agents have sed is not possible to fix(i wont mention the brand or the agents here:P, these guys do all brands). If that's too far, theres a place on Liberty Plaza first floor which unlocks phones as well. Try them. Not all unlocking is done by entering codes, one phone I unlocked they used sum kindof device and it took around 10 mins but worked. Oh and be careful, some of those unauthorized places like to switch original batteries for cheap ones, so keep an eye while they work.