Unable to use data service. Unable to send or receive MMS text messages

Thanks for your response, @Volpster.

At this time, we'd advise for you to further troubleshoot your device by resetting your device and network settings. You can do so, by proceeding with the following steps:

• If you are having connectivity concerns, you can try resetting your network settings. Swipe down from the Notification bar, then select the Settings icon > scroll to and select General management > select Reset > Reset network settings > Reset settings > select Reset to confirm.
• If a restart does not resolve your concern, you may need to perform a Factory data reset (Master reset). This will erase all data on your device and restore it to factory settings. To Factory data reset your device, swipe down from the Notification bar then select the Settings icon > scroll to and select General management > select Reset > Factory data reset.
  1. If unable to perform the standard ‘Factory data reset’ using the above steps, try the Alternate method by first powering the device off. With your device powered off, press and hold the Volume up and Side buttons simultaneously until the Android Recovery screen appears.
  2. Press the Volume down button until Wipe data/factory reset is highlighted, then press the Side button.
  3. Press the Volume down button until Factory data reset is highlighted, then press the Side button to begin the reset process.
  4. When the Android Recovery screen displays again, ensure that Reboot system now is highlighted then press the Side button.

Feel free to reach back out and let us know if these steps helped you. Thanks for reaching out to the AT&T Community. 

Lynn, AT&T Community Specialist

Consumer Cellular is your service provider, you should be calling/contacting them not AT&T.

Was your phone purchased from Consumer Cellular? If it was not, you quite possibly need to replace it.

These work on at&t, but CC isn't AT&T. 

Galaxy A11 (A115A, A115AZ, 
A115AP, A115U1)

The phone was purchased from AT&T. Consumer Cellular said the issue is with AT&T. The phone is a Galaxy A11, model # A115A.