Noncustomer check cashing charges

Noncustomer check cashing charges
so: if someone gives you a signed document, ordering their agent to pay ("pay to the order of _") you some money, the agent has the (apparently legal) right to NOT pay you that money (what their customer has ordered).
there's obviously a contractual breach somewhere there... either your client is lying to you: not paying you what they said they would, or their agent is not fulfilling it's contract to pay as its client ordered, (which ain't your problem anyway- just gimme what i'm owed, let them work out their bullshit business dealings) right?
either way, a check recipient is fucked, while either the client company or its client company is making out?
as the prole is (inevitably) the fuckee, i guess it's ok.