Please help! Excessive CPU usage

This plugin overloads the CPU usage with tons of useless requests. Is it really necessary that Packlink Pro checks EVERY FIVE SECONDS if there’s a new shipping cost for a given shipping company? Is there any way I can reduce the server requests? I’m extremely exceeding my webhost’s allowed CPU usage due to Packlink Pro and the site is sooooo slow due to this. If I deactivate the plugin, things go smoother. I disabled wp-cron and set a server-side twice-a-day cron task, but somehow it doesn’t seem to work. Please help!!!