Hmmm. I'd be inclined to straight-arm him - but that won't get you paid and may get you arrested - or worse, filled-in by him.
Who paid for the materials?
I would try a reasonable and civilised approach before sticking one on him. Sprite11 makes a very valid point - your home is your refuge, not a war zone.
I'd politely ask him if he genuinely believed you did all this work for him without expecting to be paid - and does he think that to be reasonable?
If he won't pay you for what you've done thus far, he can hardly use the excuse that you didn't do follow-up work, so you aren't getting paid for the original job.
Maybe he's skint. I know it's a compromise, but how about, "Hey if things are a bit tight for you right now, how about you give me 50 quid a week until it's paid-off", or something similar. If you remain composed and reasonable - and be seen to be making an effort to compromise, it is more difficult for the other party to be a tvvat, unless they are naturally a tvvat. If the latter is the case, I'd tell him that you are going to get paid one way or another and that you can do it the civilised way or the other way, how would he like to proceed?