If the relationship has gone bad you are better off finding someone better to work with, it sounds like you gave him a good brief and examples so there's no reason why he shouldn't have delivered. It sounds like the problem might be that while he is technically good at web, he doesn't have any design skills to create what you need, hence it looking unprofessional.
Was any staged payment agreed on e.g. a third up front? Or was it just a general xxxx euro for my website?
If thats the case you could go back and reasonably state that you think the website is only 5% finished, and arrange a percentage of payment for him, that will cover some of the hours he put in?