A millionaire withdrew all his savings and ordered his bank to check them note by note after flying into a rage when a security guard asked him to wear a face mask.
The man, known as 'Sunwear' on the social network Weibo, reportedly withdrew ¥5million (about £566,000) in banknotes from a branch of the Bank of Shanghai in China.
The sum is the maximum amount of cash that can be withdrawn, but the millionaire reportedly said he plans to go back every day until all his savings have been removed, with staff having to count it by hand each time.
In a post on social media, the millionaire expressed his dismay at the bank's service although he did not specify from his side what happened.
The bank in the Chinese city of Shanghai, however, insisted the incident simply involved a security guard asking the man to wear a face mask.
The wealthy man accused bank staff of having "the worst service attitude" in their treatment of him while boasting about having tens of millions in his account.
He added: "Because of this attitude, I can only withdraw all the money and put it in other banks."
After asking staff for the large amount of money in banknotes, he said: "It was necessary to request them to count the cash in case it fell short."
Images of the millionaire loading wads of ¥100 (£11.30) banknotes into cases and taking them to his luxury car have been widely shared on Chinese social networks.
'Sunwear' has reportedly seen his online following grow to 1.7 million as a result of his post.
He said it took two bank workers two hours to prepare his huge withdrawal with a single currency counter.
Stating that no staff member had broken any customer service guidelines, the bank added: "The client's (complaint suggested) he had higher expectations of financial services."
However, the branch said the millionaire had simply become angry after being asked to wear a face mask.
It is unclear if the man has returned to withdraw the rest of his money after the initial incident.