One of the victims, a 60-year-old man surnamed Lee, recalls the shock he experienced upon finding an automated text message from his bank alerting him that he had spent 2 million won (1,700) the night before.

He only recollected having 20,000-won worth of beer and chasers with a friend.

When confronted, the bar owner Kim claimed to have made a mistake of adding three extra zeros to the charged amount, and said he would cancel the transaction -- a promise that was never carried out.

The credit card companies could not help as long as the transaction was not retracted by Kim.

The Daejeon Dongbu police detained Kim on May 1 under charges of habitually scamming customers at his bar from October 2015 to recently. Kim is being accused of swindling close to 17 million won.

The police said Kim intentionally played on the fact that drunk people do not care much for receipts and urged people to check how much they spend when out drinking.

By Lim Jeong-yeo (kaylalim@heraldcorp.com)