As discovered in the extended discussion through comments, your system is broken. I suggest reinstalling the system completely or at least the broken packages.
To have /sbin/service again run yum reinstall initscripts.
I don't recommend it, but if you want to reinstall all the packages that fail verification, run:
yum reinstall $(rpm -q --qf '%{NAME}\n' -a | while read rpm; do rpm -V $rpm >/dev/null || echo $rpm; done)
Take note that even a modified configuration file or changed mtime might trigger a reinstall. Though the new configuration files should come up with the .rpmnew extension if you changed the original.