I offer four scenarios:
(1) I take out a loan with a bank. The bank designates an agent — often, another bank — to service the loan, so they want me to pay the second bank.
(2) I take out a loan with a bank. This time, instead of designating an agent to service the loan, it actually sells the loan itself to investors who designate an agent to service the loan. I have no idea who the investors are.
(3) I take out a loan with a bank. Because I didn’t pay on time, the bank sells the loan to a collection agency for cents on the dollar and writes off the loan, sending me (and the IRS) an IRS form 1099-C that says that I essentially have income because of the written-off debt and I have to pay taxes on that income. The collection agency demands payment of the entire amount and the original bank refuses to have anything to do with me.
(4) Same scenario as (3) except that the original bank does not send me (or the IRS) a form 1099-C.
What is my halachic obligation in each of the three circumstances regarding the debt?