Device blocked from network use
Hello, I just purchased a new sim card and prepaid plan the other day, after I traveled abroad for 9 months. After the new card was installed I right away couldn’t call, text, or use the internet data. When I try to call the automatic voice says that the device has been blocked from network use, but my phone was bought at the apple store brand new, and it was never reported lost or stolen. I also checked the IMEI code, that states that my phone is not in the blacklist. I also have already had at&t cards in the past on this device. There must be a mistake with AT&T. What can I do to make it work again? Thank you.