Someone in our team is working on this site (http://www.unbeatablelifeandcriticalinsurance.co.uk) for some time now. It was ranking for the keyword "critical illness insurance", the site disappeared completely for that keyword 2 weeks ago, what could have caused the drop? Also we have bought links from tla.
Check out: http://forums.digitalpoint.com/showthread.php?t=523738 Seems they are having the same problem. If no drastic changes were made to the pages, you might just need to wait it out.