If I recall right he was locked inside, not outside.

That was the most kafkian aspect. How could he earn more money to pay the door if it locked him inside?

In another instance, the door also didn't want to let him in without paying.

A little late, but here's the rest of the quote. He was locked in.

From the drawer beside the sink Joe Chip got a stainless steel knife; with it he began systematically to unscrew the bolt assembly of his apt’s money-gulping door.

“I’ll sue you,” the door said as the first screw fell out. Joe Chip said, “I’ve never been sued by a door. But I guess I can live through it.”

Why? I can pull up most of my documents from past few years on my mobile phone. And that’s not even fiction.