Hi need_this_fixed_pronto,
Thank you for using the Apple Support Communities.
We understand that you have two iPhones that are having issues with text messages and phone calls. We also see that you’ve already checked out the Apple Support article Update your iPhone, iPad, or iPod touch.
If the Cellular Data setting is turned off, then the iPhone will only use Wi-Fi. Learn how to View or change cellular data settings on iPhone.
The Apple Support articles below can help as well.
If you can't make or receive calls on your iPhone
If you can't send or receive messages on your iPhone, iPad, or iPod touch
If an app on your iPhone or iPad stops responding, closes unexpectedly, or won’t open
Best regards.