US cryptocurrency trading platform Coinbase has pledged to reimburse all users who have been impacted by ongoing issues which left some customer's' bank accounts being drained.

The community has been in a state of uproar over the past week after bank accounts linked to the website were overcharged, often multiple times. On Reddit, one user claimed a charge of $1,000 had been made 17 times. Another said 50 duplicate charges left $67,000 in limbo.

The website now says that Visa, its payments processor, is to blame for the costly snafu.

"We have determined that the erroneous credit and debit charges are the result of Visa reversing and recharging transactions," it said in a Twitter post Thursday (15 February).

"This was not done by Coinbase. We are working with Visa to ensure all affected customers are reimbursed.

"Over the last few months, large banks and card issuers requested that card networks change the MCC [merchant category code] for purchases of digital currency.

"Visa changed the MCC for digital currency purchases to a code that allows large banks and card issuers to charge consumers additional fees.

"Coinbase is actively working with major card networks to create a new MCC for digital currency purchases," it added. "For the benefit of consumers, we hope that this will not have additional cash advance fees. Cards provide wider access to digital currency than just bank accounts."

But many users opened up on Reddit about the troubles caused by the vanishing funds. One complained: "It's been over a week with nothing but a canned response to my ticket.

"My bank account went from very comfortable to negatives balance, not to mention extra $5 charges, and overdraft fees. As a result my rent check bounced, and my bank went further into negative for a NSF charge for $25. My landlord is not a nice person and is on my case and I have nothing to offer him. I am FREAKING OUT."

The dedicated forum page is currently swamped with negative posts about the issues.

In a company blog published Wednesday (14 Feb), Coinbase pledged that all impacted customers would be refunded, but did not confirm a timescale for the promised paybacks.

It wrote: "We deeply apologise for any frustration this may cause. We are actively working with banks, processors and networks to improve the digital currency purchasing experience."

Despite being one of the most popular ways to trade cryptocurrency, Coinbase has been hit with a slew of complaints in recent months. Officials blame mounting issues on an unprecedented number of customers who joined the platform after bitcoin's rapid spike in value last year.

In January, Coinbase users were pondering legal action after major customer service delays.