Deactivating the plugin and deleting the code?

I am using a new theme, cause my blog/website was hacked. The old theme was full width and so the two columns were usefull. Now I don’t really need them, because there’s not enough space. So I deactivated the plugin, but then the code is shown in the posts. Can I delete them somehow (not manually)?

https://wordpress.org/plugins/wens-responsive-column-layout-shortcodes/