How do you stop posgresql on centos 7?

Welcome to the world of systemd

Try something like:

service postgresql-9.2 stop

If that does not work, try to find the correct servicename:

systemctl list-units|grep postgresql

And retry above command with the part of the result just before the ".service".

On Centos 7 you should use systemctl. Ex.:

/bin/systemctl stop postgresql