Do not build links for the same keyword.
Have your links been crawled in the past 15 days? if they have and not showing this could suggest they are not quality, how are you viewing your backlinks, do you know if the backlink is indexed?
Are these backlinks paid or natural? If you paid for them, these are not great quality, Google may not be crawling them inside 15 days either, perhaps they have a sitemap suggesting a monthly crawl, if that is the case you won't see them for a while.
You should know that backlinks are not indexed based off of your site, it is not something which is in your control.