Welcome to the Q&A Forum

It sounds like you've definitely waited enough time for Google to make a change, so that doesn't seem to be an issue. I can only imagine that Google is still displaying these unwanted sitelinks because it's relevant to the users' search queries and is receiving a solid CTR. If we're talking about the traditional site links (those that include a small snippet of text, i.e, the meta description tag) you can try to tweak the meta description tag in a way to try to increase your CTR for the pages that you would ideally like to show up as a sitelink. This seems counter-intuitive in many ways, but for the pages that you want to demote, maybe you tweak the meta description tag to make it less attractive for the user to click on. Hard to comment further without knowing more specifics.

Sorry - no specific article comes to mind.  but you could pint out our answers!