there are backlinks that i am certain exist however when i do a "Find web pages that link to blahblah.com" search, nothing shows up these backlinks have existed for a few months when do these update? do they change in conjunction with other updates?
This question is asked a lot. Google only shows a small sampling of the links it actually knows. Don't worry. They know about your links.
try searching with your doman name only like if you have site named as "sitename.com" then search "sitename" in google and you'll see that G is showing those results where your site is actually located i.e. those link back pages.