You might have to change the link that you provide. You can also create a landing page that will have visitor directly go to when they search for your website.
Check this tutorial below
Did you link a product in your facebook page? then people might just have clicked to your product and not on your landing page. You should provide a link to your landing page, like "see more product" link in your product page. If people are interested then they should click on that.
If you want people to go directly to your landing page, then link that page. Make sure your landing page is not hidden. See image below