It’s about knowing your interlocutors and building relationships and trust.
This takes place outside of your usual sphere of influence and none of it can be achieved in the blink of an eye.
You need to devote time and resources to PR if you want to reach your goal, combine advertising with owned corporate content (on your website, social media, press release for instance). At the end you want to earn media – media coverage, word of mouth, retweets and more. Your are building on your value and reputation.
Media relations are indeed a long-term relationship. Do you trust a person or a corporation based on a single occurrence? Good media relations takes time. Make it happen.