Users of US cryptocurrency exchange Poloniex claim to be facing lengthy delays in verification, unresponsive customer service and balance display errors on accounts.

Complaints mounted this week on a Reddit forum dedicated to the platform, forcing it to issue updates via Twitter in an attempt to soothe concerns. Frustrations peaked Wednesday (17 January), amid market chaos caused by the abrupt closure of another exchange, BitConnect.

One Reddit user, under the name "emok032", claimed that an unspecified amount of a cryptocurrency called Tether (USDT) had not been correctly returned to an account following a cancelled transaction.

"Every time I cancel an order, the 'estimated value of holdings' gets smaller and smaller and never returns to the original total," the commenter explained. "The USDT value is never returned."

Many others, it seemed, had been facing similar issues over the previous 24 hours, as markets crashed.

"There is a huge bug going on right now and some of us lost coin balances," read one response, first reported by CoinTelegraph, an outlet that covers financial technology and cryptocurrency.

In another thread – "My ethereum is GONE!" – Reddit user "Bluewe" said that alerts had appeared on their account claiming that it had been subject to forced liquidation. "This is extremely inconvenient," the post read. "Hopefully they're just having a system issue."

In an update Wednesday (17 January), the official Poloniex Twitter account wrote: "Some balances are off and will be corrected. Forced liquidations are turned off temporarily. We're investigating reports of cancelled orders not crediting back to account balances."

But the problems may be more widespread. One Reddit user claimed that a support ticket had been left unprocessed for 158 days. "This is ridiculous now!" the commenter wrote.

Another said a verification process – needed to trade – had been unresponsive for three months, writing: "This is crazy!! Do I have to get a lawyer? Can't get access to my own money!"

The cryptocurrency boom has put strain on popular exchanges to perform smoothly despite the massive influx of new traders. Coinbase, one of the most popular exchanges, has faced similar problems in recent months and is regularly subjected to angry Reddit threads.

It remains unclear if the issues raised are indicative of the wider Poloniex userbase. According to CoinMarketCap, the US exchange is the 12th largest platform by volume traded.

Poloniex did not immediately respond to a request for comment from IBTimes UK.