can't seem to be able to change thumbnail sizes

-- url of the page with the problem -- : mywebsite.com/mypage
-- HikaShop version -- : 2.3.0
-- Joomla version -- : 3.3
-- PHP version -- : x.x.x
-- Browser(s) name and version -- : XXXXX x.x.x
-- Error-message(debug-mod must be tuned on) -- : Error_message
i can't seem to be able to change thumbnail sizes
or maybe those small images under the big images are not the thumbnails and there is somewhere else to change there size? otherwise i changed the thumbnails width and highet few times and - no effect.
Adi

ok' problem is solved, i added some css and it's good now