Switzerland’s regulated online casino market isn’t yet a year old and it already has its first payment processing scandal.

On Wednesday, Swiss media reported that some customers of two locally licensed online casinos who funded their online accounts via PostFinance – the financial services unit of SwissPost – had woken up to the discovery that their PostFinance account balances were dramatically lower than the night before, some to the tune of “several tens of thousands of francs.”

The gamblers in question were customers of online casino sites Jackpots.ch and Casino777.ch, both of which are operated by Stadtcasino Baden Group and were among the first sites to launch in the country’s new regulated online gambling market. PostFinance is considered a socially responsible payment option with Swiss online casinos because accounts can’t be overdrawn.

It seems that a software update at PostFinance on March 17 meant that customers who transferred sums from PostFinance to the online casinos saw their funds deposited into the casino accounts without being debited from their PostFinance accounts. The technical hiccup reportedly lasted until the end of May.