My dad ran his own company for twenty years so has lots of stories. Just a couple of weeks ago he told me one very similar.
He has a supplier that only partly delivers. The guy says he has trouble with his upstream supplier, says that material costs have risen unexpectedly and says that is the reason he has trouble delivering. My dad does not want substandard work so he pays some more.
As a gut feeling he drives over to the guy his site and spots the foreman. My dad asks the foreman, where is the material for my project? I paid your boss some extra cash? Foreman says there is no material for my dad's project, that material over there is for another project which also had not been running smoothly.....
If you want to make sure that money is spent on the right items, do not pay money. Instead pay the bill. But that is not always possible...