Chresten8 - we have a very effective way of getting money back from people like this - see
www.moneyclaim.gov.uk . You have to pay a small amount of money up front to file the court papers but you can add that on to what he owes you. You have to be able to prove that you have tried to recover your money before going to court - it helps massively in making sure the court are sympathetic towards you. When you get the papers you have to specify which court you want the case to be heard at - select the one nearest his premises but be sure that you also claim ALL of your travelling expenses. Most people will pay up when they receive the papers from the court but if he is really stupid he may try to fight it.
Don't just let it go, he has stolen your money, you have every right to get it back.
All the info you need is on that website, we have succesfully recovered money twice now via this route.
Best of luck,
Dave.