If a company consistently fails to pay their invoices in the correct amount due guess what?......vendors cut them off, and/or, offer merchandise or services on a COD basis only. The market will weed out the deadbeats in a hurry.
I’ve looked into this before. What happens in Trump’s case is the opposite of vendor’s dropping him. When people do inferior work for him, he refuses to pay them or he only pays them a portion of their bill (with the justification that fixing their mistakes is going to cost him money). He then typically refuses to do business with them again, and they probably wouldn’t care to work for him again either. Don Jr. explained this price adjustment based on numbers of screwups before in an interview that I remember.
By the accounts that I’ve seen, Trump promptly pays in full contractors and other businesses who provide quality work or goods. They leave happy, and he comes back to them again with more work in the future, because he now knows he can rely on them, as they know they can rely on him. Hence, he has no problem getting contractors and suppliers to work for him.
Naturally, as was recently reported, Trump has won the vast, vast majority of the law suits filed against him, which wouldn’t be the case if the people accusing him had a leg to stand on. Understandably, these people’s take on their experience with Trump is quite a bit more negative (nobody likes to admit that they screwed up and did crappy work, so of course they will come up with other excuses), and some people will unfortunately believe them.