Thats builders for you, chin up, all you can do is learn from your experiences
bit a pain being the week before xmas
did you get any part payment halfway through the job?
in future if you dont fully trust the builder insist you work direct for the customer but are willing to put a percentage on top of your price for the builder if its his job, or simply dont take on the job
i have been in this predicament before, my work was fine but the builder was shocking and he got sacked, he had taken my money off the job so there was nothing for me when he went
or if you can help it, just dont work for builders, they only make your life stressfull anyway