WCPR image sizes overriding my theme image settings

WCPR appears to be overriding the image size and thumbnail settings for my theme. I can not regenerate thumbnails to the accurate sizes as they should be for the theme because your WCPR only allows 500px and 800px sized images. What is going on? This is unacceptable as I don’t use those image sizes and it is having an affect on the image sizes produced in my product listings which has nothing NOTHING to do with your plugin WCPR. Please advise how to prevent your plugin WCPR from completely overriding my theme image size settings????? Very upset.