Paperchase
Side quest Toussaint suggested level 36 Blood and Wine
From the journal
In the end, Geralt let his temper boil over and spew forth on Giacomo Cianfanelli, the bank's owner. With fury evident on his knitted brow and waving fists, Geralt went to work on the bank's guards and thus became a persona very much non grata in that establishment.
One day, an old acquaintance ran into Geralt and pulled him aside for a chat. He was a vineyard owner for whom Geralt had completed a contract some time ago. The man had been bereft of adequate coin at the time, but, determined to compensate Geralt fairly one day, he had set up a savings account in the witcher's name at the local bank. Now that years' worth of interest had accrued and Geralt had returned to the duchy, he needed only go to the bank and collect his due.
After a long bout of trench warfare against the bank's bureaucracy, Geralt finally reached the bank's owner, Giacomo Cianfanelli. Unfortunately, Giacomo was suffering a small liquidity crisis in regards to Geralt's funds. Geralt decided to take a risk and wait a week, but only on condition that he would not have to procure any additional documents.
The witcher's visit to Cianfanelli Bank ended in a very witcher-like fashion. Geralt pummeled the guards who tried to restrain him, fought his way to the owner and in clear, concise terms made it clear he would not tolerate any more delays. He collected as much coin as he could and ended up with the dubious honor of finding himself on the list of clients no longer welcome in the bank.
Cianfanelli kept his word and not only gave the witcher his coin, but threw in a present as a bonus -- an old family heirloom. It seems the banker meant what his employees were forced to repeat ad nauseam: with him, the customer is always right and he looks after others' coin as if it were his own.