Digital currencies platform Coinbase has been working with Worldpay, Visa and Visa-issuing banks to refund the duplicate transactions that have been charged on its customers’ credit or debit card.

Users who have purchased cryptocurrencies on Coinbase between 22 January and 11 February 2018 have reported additional charges on their card statement.

Coinbase said that the erroneous charges are due to the recent merchant category code (MCC) changes requested by the card issuers and banks.

Visa denied these allegations in a statement that read: “Visa has not made any systems changes that would result in the duplicate transactions cardholders are reporting. We are also not aware of any other merchants who are experiencing this issue.

“We are reaching out to this merchant’s acquiring financial institution to offer assistance and to ensure cardholders are protected from unauthorised transactions.”

However, Coinbase posted a joint statement from Visa and Worldpay on its website confirming that the ‘duplicate transactions have been reversed and appropriate credits have been posted to cardholder accounts.’