Thanks for all your advice guys. As the guy was a friend of a friend, I thought he would have been ok as he was introduced by someone I true, but after my experiences with his bad attittude and him now appearing to be avoiding paying me, I shouldn't have been so trusting.
I think I will send him a letter by recorded post to demand he contact me within the next 5 days and then send his details to a solicitor to send him a further letter from here. If he still doesn't reply, I will just speak to the agency so that they know what has happened and will suggest that they not provide him with future work; if they don't co-operate I will then inform the end client that they are using copyrighted code on their website that hasn't been paid for.
Leadwerks & D4NM4N - Ha ha, you methods sound... tempting.
I think I will send him a letter by recorded post to demand he contact me within the next 5 days and then send his details to a solicitor to send him a further letter from here. If he still doesn't reply, I will just speak to the agency so that they know what has happened and will suggest that they not provide him with future work; if they don't co-operate I will then inform the end client that they are using copyrighted code on their website that hasn't been paid for.
Leadwerks & D4NM4N - Ha ha, you methods sound... tempting.