Try to disable cropping and upload images of equal size. Please do not edit theme templates code. Your site is not in English seems that you are trying to set images for posts, not for products (ajustes.png) the Default WooCommerce does not have the option to configure image size. Our theme does Appearance > Customize > WooCommerce > Product images > disable Cropping.
The setting in Appearance > Customizes> WooCommerce > Product Images now because you have set image size in WP Barkey Builder 300×350 http://prntscr.com/jaa7nf
This configuration overwrite the settings in Appearance > Customizes> WooCommerce > Product Images and in result the image is uploaded in this size: http://prntscr.com/jaa86r and not in 700
You need correct the settings of Product grid element.
I would recommend you to put there “full” or leave empty. When you put “full” images are uploaded as they are and then resized depending on quantity in the row, but quality would not suffer. Put full without quotations.