South Korean cryptocurrency exchange Bithumb has asked a local court to freeze seven bitcoin BTC$71,149.52, worth roughly $8 million, that remain unreturned after a February payout error. The move escalates a dispute with a small group of users who refused to return the funds.

The exchange said it began a provisional seizure, a pre-lawsuit step that blocks a debtor from moving assets, according to local media. A civil case is expected to follow.

It all began on Feb. 6, when the exchange ran a promotion intended to pay 620,000 won (~$460) to 249 winners. Staff mistakenly entered “BTC” instead of “KRW,” which led to the system crediting each winner with 620,000 bitcoin on Bithumb’s internal ledgers. This was human error that briefly made it look like the exchange had created over $40 billion worth of BTC.

Within minutes, some users sold roughly 1,788 BTC before Bithumb froze accounts, pushing its BTC/KRW price down to the low 80 million won ($54,000) range.

The exchange reversed most entries and recovered the bulk of sold coins, but about 12.3 billion won ($8.3 million) remained outstanding. That figure has since fallen to seven bitcoin after months of outreach.

Legal experts in Korea, per the local reports, say such cases fall under unjust enrichment, meaning recipients must return the assets. If coins were sold, users may need to buy them back at higher prices to repay.

This episode highlights how a human error, combined with the speed and irreversibility of crypto transactions, can turn minor mistakes into multi-million–dollar crises.

Bithumb is the second-largest cryptocurrency exchange in South Korea, according to Coingecko, with a 24-hour trading volume of $388 million, trailing only Upbit, which recorded $788 million over the same period.