[Plugin: eshop] how to get rid of Class F?

Hi all,

I am using eshop version 6.0.2 in combination with the eStore theme.

I’ve chosen shipping Method 3 (one overall charge no matter what quantity is ordered) and though I am offering free shipping within zones 1 (of 3), I am not offering any free shipping on other zones, but zone F (Free) is showing up on the Shipping Costs page and I do not want that to happen (since it does not make sense). How can I prevent Class F from appearing?

http://shop.prettyforest.com/?page_id=183

Thanks in advance for any usable feedback!