Hello Vberg001,
It sounds like you were running into an issue with having no service on your iPhone and were not able to complete a cellular update. Then, you were trying to erase the device and saw this message appear. Do we have that correct?
First, check to see if your iPhone meets the criteria for the iPhone 7 Repair Program for "No Service" Issues
If not, take a look at the steps in this article for help with the issue regarding service to your iPhone: If you see No Service or Searching on your iPhone or iPad
Then, if there was a carrier settings update available on the iPhone, this link will help with steps to take to complete that: Update your carrier settings on your iPhone or iPad
If you're unable to get that completed, you would need to seek service for your iPhone. Reach out here for more information: Get Support
Take care!