Would you battle a business owner over $4?

A Harvard Business School associate professor’s emails to a Chinese restaurant owner are going viral after the professor was charged $57.35, $4 more than he was planning to pay for his order.

Sichuan Garden owner Ran Duan said that the online menu had not been updated to reflect the price changes. But professor Ben Edelman sparred with Duan over the charge, accusing Duan of intentionally violating a Massachusetts consumer protection law.

Edelman said that he was now entitled to three times the amount of the overcharge, and that he had contacted the authorities.

Duan said he was happy to refund the $4, but would wait for authorities to see if he needed to pay the $12.  

The business owner said that the email exchange broke his heart.

“I have worked so hard to make our family proud and to elevate our business,” he said.

Meanwhile, Edelman claimed that he was applying the same rules to the Chinese restaurant as he would to a larger business.

Later, he wrote on his website:

Having reflected on my interaction with Ran, including what I said and how I said it, it’s clear that I was very much out of line. I aspire to act with great respect and humility in dealing with others, no matter what the situation. Clearly I failed to do so. I am sorry, and I intend to do better in the future.

Read the email exchange on Boston.com.