Carpenter trouble

I made a mistake. I paid the carpenter.
Now he won't return to finish his job.
I didn't think I'd paid the whole amount. It was the landlord who did the negotiating and I thought there was still a little more before it was the total price.
Nope.
He finished the kitchen cupboards and asked for money. Then he took all those bills with a hungry look in his eye and slept late the next day (so I assume) knowing he wouldn't come back to finish the other little odd jobs around the place.
Sigh.
Why do I have to be so constantly on guard for everything? Can't I trust that when I hire (and pay) a person to do a job, he will then do it?
And to do it well. That would be another nice idea.
Every time I look at those kitchen cupboards I see another small thing that wasn't done right. As if doing the job right wasn't important because I would never notice anyway. But I do. And it makes me sick because those cupboards weren't cheap and apparently now it's my fault they aren't nice because I paid him.