^^^^^^

Mortgage backed securities were sliced diced and sold so much, I doubt the Citibank worker is really calling up some investor in China who bought the mortgage and negotiating with him.

It's more likely the role this 'investor' will play is the same role played by the car dealership sales manager when you got to buy a car and the salesperson says, "I'd love to accept your offer, but let me run it by my manager," then walks out of the room, has a coffee, and comes back five minutes later saying his manager wants another grand but will throw in an undercoat and some floor mats for %50 off.

Citi dose not own the loan and is just a processor.  The loan is owned by investors.  Citi was hired by the investors to collect the payments and deal with the homewners.  This is pretty common for loans made during the bubble where there were lots of investors willing to buy mortgage securities.