A logo is nothing on it's own. Many agencies, like the one in the article, push a 'rebranding' that should include a brand/style guide on how to use its compone

A logo is nothing on it's own. Many agencies, like the one in the article, push a 'rebranding' that should include a brand/style guide on how to use its components, thereby justifying the price. If OP didn't receive such a guide he definitively got ripped off.