Containers running on virtualised servers such as OpenVZ or Virtuosso have a shared kernel (and shared memory) with every VPS on that machine. This means that the container time will be the same as the host computer's time, and the only person who can control that is the server administrator.
You should still be able to edit the timezone of the VPS, though, using:
mv /etc/localtime /etc/localtime.backup
ln -s /usr/share/zoneinfo/ZONEINFO /etc/localtime
ZONEINFO with your timezone info. A full list of the timezones is available here on Wikipedia. You need to use the text in the "TZ" column for your region in place of the
ZONEINFO. Then reboot the server or restart any services for the new time settings to take effect.
Changing the timezone is probably what your web host did when you asked them to update your time settings for you, so it's unlikely you'll need to do this if you've already asked them to change it.
You might also find that there are other restrictions in place too. (e.g. Running
yum to update the system may fail.) If this bothers you, you could switch to a VPS provider who uses XEN or KVM for virtualisation instead of OpenVZ or Virtuosso, because XEN and KVM containers each have their own custom kernel. You will probably find your VPS needs more memory if you do this, though, because XEN and KVM can be more resource intensive.