They have different SLAs for certain issues: https://www.ovh.com/us/dedicated-servers/sla.xml

Does the server boot? If so, you should use http://docs.ovh.ca/en/guides-ovh-rescue.html#hardware-check which should flag it to them I believe.

If the server doesn't boot it should have been picked up by their monitoring systems (I believe this is "Level 1").

Have you tried calling them?