News Courtesy of Yoast.com:
It’s one of the most frustrating problems you can encounter when working on your site’s SEO: one of your pages is ranking well in Google, but it’s ranking for the wrong keyword. You haven’t optimized this page for the keyword it’s ranking for, and the page you did optimize for that keyword, is nowhere to be found in the results pages.
It can be harmful to your CTR and conversion rate when the wrong page for a keyword pops up in the results pages, but what can you do about it? First, you should make sure the page you actually want to rank for your keyword can be properly crawled and indexed. If that is indeed the case, take a long, hard look at how you’ve optimized your content. Odds are, your content and your internal linking structure aren’t as good as you think at showing Google which page to rank for which keyword.
Ryan’s Take 
It definitely is frustrating when you spend a lot of time optimizing a page for a keyword and not have it shown on the results pages. Even more so when another page that you are not targeting is listed for that keyword. Unfortunately, we can’t control how Google sees our websites and pages. All we can do is follow their guidelines and steer Google in the right direction.
You would think that a properly formatted title tag and meta description would make for an automatic snippet. However, it is just a mere suggestion. Most of the time Google will follow that suggestion. However, it is a complex system and anyone outside of the company can’t know the exact methods used to generate such information. The same can be said for keyword ranking.
If you find a particular page that you haven’t optimized ranking for a targeted keyword, analyze that page. Check your internal and outbound link structure. Consider any dynamic content that might be affecting it. Perhaps a blog widget is providing content and altering the results. Once you start to break down the offending page piece by piece, you should have some clues to go on. If all else fails, as Yoast suggests, consult a reputable SEO agency. They should be able to pinpoint any trouble areas on that page.
