I have sympathy for people subject to the vagaries of corporate payment settlement terms, but when you agree to net 60 you may not get paid for 60 days. To get paid sooner will cost something.
That there are intermediary companies offering cash-flow for a fee isn't exactly new either.
At the very least one should be charging ~6% more (1.02 ^3) for net 90 terms, along with Credit Card like rates for missed payments. A good rule of thumb in America is if they have lawyers, you need lawyers.