iPhone says no service error - code 1667

Start here, If you see No Service or Searching on your iPhone or iPad - Apple Support

Also, this is not a chat service, and you have to wait for someone to read and respond to your post. Also, you are not addressing Apple here, this is a user to user support forum and Apple does not participate here.

With regards to error 1667: Check your hardware - Apple Support

Also see: iPhone 7 Repair Program for "No Service" Issues