Hi! I have an iPhone 4 with a straight talk sim. I just recently updated to 7.0.3 . I cannot use any data but I can send and receive MMS and make phone calls. I'm not very tech smart so I'm not sure how to fix this. Please help!
From your phone go to unlockit.co.nz and it will allow you to easily set up your APN settings. If you do not know what that is just google " Change iPhone APN settings"
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I guess I should have mentioned that you should connect to wifi first
Getting a new sim could be the last resort, but I would reset the network settings first and see how that works. I just set up a gentlemen and watched him run through the same settings with his iOS 7 device and it worked fine. Best of luck.