I can't seem to find a straight answer on this, so I'm hoping someone here can help. I have an iPhone 4 running iOS 7.0.4, and the phone is LOCKED for AT&T. I'm trying to get access to the APN settings to get MMS working on Consumer Cellular. 3G works fine (besides being horribly inconsistent in speed...). I have an unactivated Ultra Mobile sim card (T-Mobile network). I have followed the sim swap instructions, but the cellular network option does not appear when I have the UM sim card in. The question is, will I ever see this option with this config and locked? I have seen some comments suggesting people have got it to work with locked phones, but with older iOS. I want to make sure I've exhausted my options before considering paying to unlock. Thanks in advance for you help!