The contractor owed me the freight for the engineering vehicle and asked him for it. He always said that the boss didn't give him money. What should I do?

If you don't pay back the outstanding freight, there are two ways to ask for it:

The first is to increase the frequency and intensity of demand. It is only natural that whoever owes money to whom should pay back. If you say the boss won't pay, go to the boss and see what the problem is.

Second, if things go wrong, go to the labor inspection brigade, or go to court to sue, and designate the contractor as Lao Lai, and whoever defaults on the project payment will bear legal responsibility.