How to get all posts or users who shared a link to a site in social. networks?

Question

Facebook

The task is to collect a list of the maximum number of users who have shared a link to the site, preferably those who clicked on the share button located on the project site.
Interested in: facebook, twitter, vk.
Rummaged through many different services and api methods (primarily facebook and twitter).
For example: facebook - shows 1000+ "shares" and "likes", and at the same time 0 in the search; vk - shows 2000 mentions in the search, and at the same time, through the api method likes.getList and newsfeed.get return much less.
Time is running out, and even an approximate tool has not been found, perhaps one of the readers has met?

Answer 1

amplifr.com should help