If you got an error message that the sim you tried to use was not supported, then your phone was not unlocked to be used on another network. Your carrier needs to unlock your phone. They are the only ones that can do it. See here: https://support.apple.com/en-us/HT201328. Go back and talk to your carrier. Find out what they mean that it is not them keeping your phone locked.
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If you got an error message that the sim you tried to use was not supported, then your phone was not unlocked to be used on another network. Your carrier needs to unlock your phone. They are the only ones that can do it. See here: https://support.apple.com/en-us/HT201328. Go back and talk to your carrier. Find out what they mean that it is not them keeping your phone locked.
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