Traveling to Japan and found out that my phone is a locked one, can't add other services besides AT&T, but I bought it straight from Samsung so why is that??
As @ChaosSaber mentioned, if you purchased it from Samsung, but chose your carrier as AT&T, rather than factory unlocked, it will be locked to AT&T. For future reference in purchasing, always choose the factory unlocked, especially if you travel and want to add a foreign sim
If you paid the phone in full, see what AT&Ts policy is on unlocking it. Some carriers require at least 3 months on their service (for the individual phone, not the user) before they will unlock it and it has to be fully paid for.
@white_junWJ FYI, AT&T's international plan is only $12/day and is only charged for the days that you actually use it. It worked great for me in Seoul, Korea and Paris, France.
