Thumbnail image sizing

I am using the Church theme for my wordpress affiliate store. You can see a post here at http://www.surfsection.com/shop/mens-watches/nixon-mens-watch-42-20-chrono-white-2/ You’ll notice that the twoo product thumbnail images are way too big. I’ve specified their size in WooCommerce to 90×90, but it looks like the theme is overriding this sizing. Is this true? If so, how can I change (just the thumbnail sizing) to 90×90?