Wondering if anyone has had any similar encounters or if anyone has any helpful advice for me. Here's my story (sorry for the length):

6 weeks ago I get a call from a man in the US saying hes seen my online portfolio and asked if I could do some logo design work for his company. I checked out his company's website and in fact they used to do business with the previous company I worked for in London so I thought they were fairly trustworthy.

I intially asked him to sign a contract between him and my umbrella company. He suggested that it would be easier if he just took me on for 2 days and I invoiced him for that and he would wire me the money. And from then on if he liked my work he would take me on and pay me one day in advance to avoid any issues. I was a little unhappy with this but agreed because I havent been freelancing long and dont like putting people off by making them sign loads of forms.

I started working but was getting very little feedback from him by email from my logo concepts. Logo design is heavily dependant on feedback and I was getting virtually none. In fact I was waiting around for several days for feedback. This was time that I was not getting paid for nor was I able to use this time to start another project. I was in limbo. I was sending emails with detailed explanations of my thinking and my process along with images and all sorts. When eventually I DID get a response it was normally "Not really keen on Version 1, Version 2 is better" - pretty frustrating.

So after one days official "work" I get an email from him saying "We have really not found anything we liked even with the second batch. I think it would be fair to say to stop at this point, I will pay you in full. The wire will be sent tomorrow."

As you can imagine I was pretty annoyed. Not only was I getting very little direction but I was doing exactly what I was asked with the direction that I was being given. To then get told he doesnt like it was a bit insulting. However he had my invoice already so I didnt reply but just waited for payment.

One week went by, no money. I chased via email. 2 weeks, nothing. Chased again. 3 weeks, chased again. Eventually after 4 weeks I get an email saying the money has gone through. I checked and it was only for HALF the invoice amount! :mad2 ie one days work! I was very angry since I took out 5 days of my time to work on this for him. And despite my very understanding and cooperative nature during the project I get told my work is crap and hes paying me for one day. He even said he would pay me IN FULL. Currently Im chasing him for the full amount on my invoice. To really rub salt in to the wounds he has let the international bank transfer fee be incurred by me.
What should I do?