“docker images” shows image, “docker rmi” says “no such image” or “reference does not exist”

This means that your docker state is corrupted and you need clear the complete state

sudo service docker stop
sudo rm -rf /var/lib/docker
sudo service docker start

This will start docker fresh without any existing data. Try pulling deleting the image after this and see if all works. If it doesn’t then there is some issue that needs to be looked into