Thanks ladies for your input I knew I was right but it is true that I didn't perform the service so thought I would ask your opinions. Anyway I decided to keep it in the end for my trouble and haven't heard from him since so maybe he was too embarrassed to call back when he was conscious/sober.
Bank transfers are non-refundable nowadays without a lot of effort anyway and I checked my account for any hint of this being a possibility (moved the money into my everyday account obviously) and there was none so guess he's chalking it up to weekend stupidity.