is my iphone 4 factory unlocked

ok guys heres the deal i recently bought an iphone 4 off of my friend i went to a place to factory unlock it and they said they can i paid $100 to unlock it so i can use the phone internationaly but i have no way of test the phone. please help i have to know if this phone is unlocked or if i got scammed

Side notes:

GSM 16gb iphone 4

originally locked to At&t

says carier 12.0

running IOS 5.1.1

model:MC608LL

MF:04.12.01

NOT JAILBROKEN

also

when i put a sim in the trey it shows a red bubble over the phone icon saying i have a voicemail but cannot call my voicemail and keep saying searching No service

PLEASE HELP ME OUT THANKS FOR TAKING TIME TO ANSWER MY QUESTION