Icon design is a difficult thing to do well. It takes time and iteration. The image needs to communicate something very quickly without words. Oftentimes designers make concessions that can be misinterpreted. Icons that span cultures and languages layer on complexity.
This aspect of graphic design is usually the first budget line item to be axed in a project. Stock websites and bad logo designers flood the marketplace with icons. Unfortunately, they are poor attempts to communicate an unknown to the masses. On your next project, I would strongly urge you to commission custom icons that truly communicate what you want.