Social sharing shares category image instead of product

Hi guys,

I'm just wondering if anyone can help me with this issue.
Its about product images On the site, the product is showing all the images fine, I checked and saw all the images links were from cache folder.

The issue now is whenever I share a page on facebook or other sharing sites, it grabbed my category image and not product images.

Example link: http://www.mestibeli.com/Heatvape-Coil- ... ster-Black

can someone help?

Thank you in advance.