Some people’s greed knows no bounds.

Ben Edelman, associate professor at Harvard Business School, ordered what he thought was $53.35 worth of Chinese food from Sichuan Garden, a Chinese restaurant in Boston’s Brookline Village.

Edelman, sharp as he is, figured out that he was overcharged by $4 dollars.

Read Edelman’s emails to Ran Duan, whose parents founded Sichuan Garden, below. In the exchange, Edelman harasses Duan in an attempt to get $12 from the restaurant after they overcharged him $4. Edelman also says things like:

“It strikes me that merely providing a refund to a single customer would be an exceptionally light sanction for the violation that has occurred.”

Keep in mind, the average salary for a Harvard Associate Professor is $120,900 a year

Here’s what Duan had to say about the whole fiasco: “I have worked so hard to make my family proud and to elevate our business. It just broke my heart.”

Read the full email exchange between Edelman and Duan below.